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Jacob Mashilo
Limpopo Department of Agriculture and Rural Development, Towoomba Research Station, Bela-Bela 0480, South Africa

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Journal article
Published: 23 August 2021 in Agronomy
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Lagenaria siceraria (Molina) Standl is an important horticultural and medicinal crop grown worldwide in the food and pharmaceutical industries. The crop exhibits extensive phenotypic and genetic variation useful for cultivar development targeting economic traits; however, limited genomic resources are available for effective germplasm characterization into breeding and conservation strategies. This study determined the genetic relationships and population structure in a collection of different accessions of bottle gourd derived from Chile, Asia, and South Africa by using single-nucleotide polymorphism (SNP) markers and mining of simple sequence repeat (SSR) loci derived from genotyping-by-sequencing (GBS) data. The GBS resulted in 12,766 SNPs classified as moderate to highly informative, with a mean polymorphic information content of 0.29. The mean gene diversity of 0.16 indicated a low genetic differentiation of the accessions. Analysis of molecular variance revealed less differentiation between (36%) as compared to within (48%) bottle gourd accessions, suggesting that a random mating system dominates inbreeding. Population structure revealed two genetically differentiated groups comprising South African accessions and an admixed group with accessions of Asian and Chilean origin. The results of SSR loci mining from GBS data should be developed and validated before being used in diverse bottle gourd accessions. The SNPs markers developed in the present study are useful genomic resources in bottle gourd breeding programs for assessing the extent of genetic diversity for effective parental selection and breeding.

ACS Style

Rodrigo Contreras-Soto; Ariel Salvatierra; Carlos Maldonado; Jacob Mashilo. The Genetic Diversity and Population Structure of Different Geographical Populations of Bottle Gourd (Lagenaria siceraria) Accessions Based on Genotyping-by-Sequencing. Agronomy 2021, 11, 1677 .

AMA Style

Rodrigo Contreras-Soto, Ariel Salvatierra, Carlos Maldonado, Jacob Mashilo. The Genetic Diversity and Population Structure of Different Geographical Populations of Bottle Gourd (Lagenaria siceraria) Accessions Based on Genotyping-by-Sequencing. Agronomy. 2021; 11 (8):1677.

Chicago/Turabian Style

Rodrigo Contreras-Soto; Ariel Salvatierra; Carlos Maldonado; Jacob Mashilo. 2021. "The Genetic Diversity and Population Structure of Different Geographical Populations of Bottle Gourd (Lagenaria siceraria) Accessions Based on Genotyping-by-Sequencing." Agronomy 11, no. 8: 1677.

Review
Published: 24 May 2021 in Euphytica
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Genetic improvements for yield-component traits in bread wheat (Triticum aestivum L.) have resulted in substantial contributions to wheat yield increases globally. Conversely, yield gains have tended to reduce genetic gains for grain quality traits, requiring a strategic breeding approach for simultaneous improvement of grain yield and grain quality. The objective of this review is to highlight breeding progress on genetic improvement of agronomic, physiological, and biochemical traits, grain quality, and bread-making attributes in bread wheat. Genetic gains for agronomic, physiological, and biochemical yield-component traits and their influence on yield response and genetic potential are discussed. Genetic changes in grain quality traits and bread-making attributes and how they are influenced by gains for yield and yield-component traits are also presented. Also, the paper presents wheat genetic resources to enhance genetic gains for yield-component and quality traits. Perspectives on future breeding efforts to improve genetic gains for yield, yield-related traits, and grain quality traits are discussed. Genetic gain in grain yield of 15.3 ha−1 year−1 (0.7%) were reported for Siberia, 15.3–57.5 kg ha−1 year−1 for Canada, 15.3–103.5 kg ha−1 year−1 for China, 15.3–31.0 kg ha−1 year−1 for Iran, 33.9–34.8 kg ha−1 year−1 for Brazil, 33.1–40 kg ha−1 year−1 for Mexico, 14.6–30.4 kg ha−1 year−1 for the USA, 18 kg ha−1 year−1 for Australia, and 58.0 kg ha−1 year−1 for Turkey. The most important agronomic traits that contributed to significant improvements in yield gains include short plant height, high biomass production, higher harvest index, increased number of kernels per spike, and greater thousand kernel weight.

ACS Style

Zamalotswa Thungo; Hussein Shimelis; Alfred Odindo; Jacob Mashilo. Genetic gain for agronomic, physiological, and biochemical traits and quality attributes in bread wheat (Triticum aestivum L.): a meta-analysis. Euphytica 2021, 217, 1 -33.

AMA Style

Zamalotswa Thungo, Hussein Shimelis, Alfred Odindo, Jacob Mashilo. Genetic gain for agronomic, physiological, and biochemical traits and quality attributes in bread wheat (Triticum aestivum L.): a meta-analysis. Euphytica. 2021; 217 (6):1-33.

Chicago/Turabian Style

Zamalotswa Thungo; Hussein Shimelis; Alfred Odindo; Jacob Mashilo. 2021. "Genetic gain for agronomic, physiological, and biochemical traits and quality attributes in bread wheat (Triticum aestivum L.): a meta-analysis." Euphytica 217, no. 6: 1-33.

Research article
Published: 01 April 2021 in Journal of Crop Improvement
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The new generation sweetpotato [Ipomoea batatas L. (Lam.)] varieties are valued as dual-purpose types for food and fodder in the crop-livestock mixed-farming systems in sub-Saharan Africa. The objective of this study was to determine the genetic diversity present among dual-purpose sweetpotato genotypes using simple sequence repeat (SSR) markers and phenotypic traits to identify complementary genotypes for direct production and breeding. Twenty-four sweetpotato genotypes were genotyped using nine selected and highly polymorphic SSR markers and dual-purpose phenotypic traits. The genotypes were field-evaluated using a randomized complete block design with three replications in two representative locations in Rwanda. Genotypes differed significantly (p < 0.05) for dual-purpose traits and other assessed phenotypic traits. Genotype “Ukerewe” had the highest fresh root yield (18.24 t ha−1), followed by genotype ‘8–1038ʹ (17.63 t ha−1). The top-performing genotypes for fresh vine yield were “Wagabolige” (23 t ha−1) and ‘NASPOT13ʹ (21.64 t ha−1). The mean expected heterozygosity value was 0.69, indicating adequate genetic variation in the tested germplasm. Cluster analysis grouped the genotypes into three distinct groups, which aided in the identification of genotypes with high fodder and storage root yields, which were SPK004 and K5132/61 from Group I; 4–160, Ukerewe and RW11-2910 from Group II; and RW11-1860, Wagabolige and 2005–179 from Group III. The identified genotypes should be useful genetic resources for production and development of high-performing dual-purpose sweetpotato cultivars in Rwanda.

ACS Style

Damien Shumbusha; Hussein Shimelis; Mark Laing; Jacob Mashilo. Genetic analysis of dual-purpose sweetpotato genotypes using simple sequence repeat markers and phenotypic traits. Journal of Crop Improvement 2021, 1 -20.

AMA Style

Damien Shumbusha, Hussein Shimelis, Mark Laing, Jacob Mashilo. Genetic analysis of dual-purpose sweetpotato genotypes using simple sequence repeat markers and phenotypic traits. Journal of Crop Improvement. 2021; ():1-20.

Chicago/Turabian Style

Damien Shumbusha; Hussein Shimelis; Mark Laing; Jacob Mashilo. 2021. "Genetic analysis of dual-purpose sweetpotato genotypes using simple sequence repeat markers and phenotypic traits." Journal of Crop Improvement , no. : 1-20.

Review
Published: 19 March 2021 in Plant Breeding
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Breeding new and high performing cultivars with market‐preferred traits take more than 10 years in the absence of an integrated pre‐breeding programme. During the early phases of breeding a significant amount of time, space and resources are invested in the selection and genetic advancement stages after initial crosses are performed with parental genotypes. Speed breeding has the potential to reduce the time required for cultivar development, release and commercialization. The objective of this review was to present the key opportunities and challenges of speed breeding to guide pre‐breeding and breeding programmes. Key challenges of speed breeding include: (a) access to suitable facilities, (c) staff trained in the protocol, (b) adopting major changes to breeding programme design and operations, and (d) the need for long‐term funding. The current review highlights the potential advantages of speed breeding for the successful development and release of pure line cultivars in self‐pollinated crops in ~5 years versus 8 to 10 years when using traditional methods.

ACS Style

Maliata Athon Wanga; Hussein Shimelis; Jacob Mashilo; Mark D. Laing. Opportunities and challenges of speed breeding: A review. Plant Breeding 2021, 140, 185 -194.

AMA Style

Maliata Athon Wanga, Hussein Shimelis, Jacob Mashilo, Mark D. Laing. Opportunities and challenges of speed breeding: A review. Plant Breeding. 2021; 140 (2):185-194.

Chicago/Turabian Style

Maliata Athon Wanga; Hussein Shimelis; Jacob Mashilo; Mark D. Laing. 2021. "Opportunities and challenges of speed breeding: A review." Plant Breeding 140, no. 2: 185-194.

Original article
Published: 17 March 2021 in Plant Breeding
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The extent of phenotypic variation among Sesame germplasm influences the expression of economic traits and the response to selection. The objective of this study was to determine the variance components, heritability (H2) and association of seed and oil yield‐related traits in Ethiopian sesame germplasm to guide breeding. One hundred sesame germplasm were evaluated under field conditions in two locations in a 10 x 10 lattice design with two replications. The findings revealed higher genotypic coefficient of variation, H2, and genetic advance for number of primary branches (NPB), number of secondary branches (NSB), thousand seed weight (TSW), seed yield per hectare (SYH) and oil yield per hectare (OYH), suggesting high genetic gains can be achieved through selection. Higher direct effects of OYH and NSPC were recorded on SYH, while SYH, NCPP and TSW had higher direct effect on OYH. The genotypes Hirhir Kebabo Hairless‐9, Setit‐3, Orofalc ACC‐2, Hirhir Humera Sel‐6, Setit‐1 and ACC‐NS‐007(2) were found superior and the selected genotypes should promote for further field stability evaluation, which might be utilized in future sesame breeding programmes and production.

ACS Style

Desawi H. Teklu; Hussein Shimelis; Abush Tesfaye; Jacob Mashilo. Genetic diversity and association of yield‐related traits in sesame. Plant Breeding 2021, 140, 331 -341.

AMA Style

Desawi H. Teklu, Hussein Shimelis, Abush Tesfaye, Jacob Mashilo. Genetic diversity and association of yield‐related traits in sesame. Plant Breeding. 2021; 140 (2):331-341.

Chicago/Turabian Style

Desawi H. Teklu; Hussein Shimelis; Abush Tesfaye; Jacob Mashilo. 2021. "Genetic diversity and association of yield‐related traits in sesame." Plant Breeding 140, no. 2: 331-341.

Research article
Published: 06 March 2021 in Genetic Resources and Crop Evolution
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Citron watermelon [Citrullus lanatus var. citroides (L.H. Bailey) Mansf. ex Greb.] is an important genetic resource serving for food, feed, and breeding dessert watermelon (C. lanatus var. lanatus) and other cross-compatible species. Wide phenotypic variation exists among South African citron watermelon landraces which are yet to be systematicaly assessed for diverse uses and cultivar design. The objective of this study was to assess phenotypic diversity of citron watermelon landrace accessions of South Africa and to select desirable genotypes with suitable agronomic and horticultual traits for direct production, breeding and conservation. Thirty six citron watermelon landrace accessions were evaluated under field conditions in two seasons using a 6 × 6 alpha lattice design with three replicates. Data on key qualitative and quantitative traits were collected and subjected to non-parametric and parametric statistical analyses. The accessions showed wide phenotypic variation and unique traits for genetic improvement. Positive and significant correlations (p < 0.001) were recorded between total fruit yield per plant with plant height (r = 0.64), number of harvestable fruits (r = 0.70), number of marketable fruits (r = 0.73) and marketable fruit yield (r = 0.96). Seed yield per plant positively and significantly (p < 0.001) correlated with number of male flowers (r = 0.68), plant height (r = 0.61) and total fruit yield (r = 0.79). Prinicipal component analysis identified nine components which accounted for 86.38% of total variation amongst accessions for assessed phenotypic traits. Citron watermelon accessions WWM16, WWM67 and WWM79 were high-yielding suitable for fruit production for food or livestock feed. Accessions namely WWM03, WWM09, WWM16, WWM39, WM64 and WWM76 produced high fruit number and marketable fruit yield per plant which are recommended as parental genotypes for breeding. Furthermore, accessions WWM04, WWM15, WWM24, WWM28, WWM46, WWM66, WWM68, WWM76 and WWM79 were selected with higher seed production for the food or feed industry. The study recommends citron watermelon accessions such as WWM14, WWM16, WWM39, WWM41, WWM67 and WWM79 for use as leafy vegetables owing to their profuse branching ability and longer vine production. Whereas accessions including WWM03, WWM17, WWM35, WWM40, WWM50, WWM67, WWM79 and WWM85 are selected with larger fruit size. Accessions WWM05 and WWM09 are sour-flesh types which are suitable genetic stocks for breeding sweet-and-sour dessert watermelons. Orange-fleshed accessions such as WWM03, WWM04, WWM46, WWM64, WWM66 and WWM67 are recommended for fresh consumption, cooking, processing or variety design. Accessions WWM02, WWM03, WWM08, WWM14, WWM16, WWM23, WWM38, WWM40, WWM41 and WWM67 have red and white seed coat colour which are superior selections to prepare roasted citron watermelon seed snack.

ACS Style

Richard Mantlo Ngwepe; Hussein Shimelis; Jacob Mashilo. Variation in South African citron watermelon (Citrullus lanatus var. citroides [L.H. Bailey] Mansf. ex Greb.) landraces assessed through qualitative and quantitative phenotypic traits. Genetic Resources and Crop Evolution 2021, 68, 2495 -2520.

AMA Style

Richard Mantlo Ngwepe, Hussein Shimelis, Jacob Mashilo. Variation in South African citron watermelon (Citrullus lanatus var. citroides [L.H. Bailey] Mansf. ex Greb.) landraces assessed through qualitative and quantitative phenotypic traits. Genetic Resources and Crop Evolution. 2021; 68 (6):2495-2520.

Chicago/Turabian Style

Richard Mantlo Ngwepe; Hussein Shimelis; Jacob Mashilo. 2021. "Variation in South African citron watermelon (Citrullus lanatus var. citroides [L.H. Bailey] Mansf. ex Greb.) landraces assessed through qualitative and quantitative phenotypic traits." Genetic Resources and Crop Evolution 68, no. 6: 2495-2520.

Review
Published: 19 February 2021 in Sustainability
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Citron watermelon (Citrullus lanatus var. citroides (L.H. Bailey) Mansf. ex Greb.) is an underexploited and under-researched crop species with the potential to contribute to crop diversification in Sub-Saharan Africa. The species is cultivated in the drier parts of Southern Africa, mainly by smallholder farmers who maintain a wide range of landrace varieties. Understanding the molecular and morpho-physiological basis for drought adaptation in citron watermelon under these dry environments can aid in the identification of suitable traits for drought-tolerance breeding and improve food system resilience among smallholder farmers, thus adding to crop diversification. This paper reviews the literature on drought adaptation of Citrullus lanatus spp. (C3 xerophytes), using the systematic review approach. The review discusses the potential role of citron watermelon in adding to crop diversification, alternative food uses, and potential by-products that can be processed from the crop, and it analyzes the role of Sub-Saharan African farmers play as key actors in conserving citron watermelon germplasm and biodiversity. Finally, the review provides a summary of significant findings and identifies critical knowledge gaps for further research.

ACS Style

Takudzwa Mandizvo; Alfred Oduor Odindo; Jacob Mashilo. Citron Watermelon Potential to Improve Crop Diversification and Reduce Negative Impacts of Climate Change. Sustainability 2021, 13, 2269 .

AMA Style

Takudzwa Mandizvo, Alfred Oduor Odindo, Jacob Mashilo. Citron Watermelon Potential to Improve Crop Diversification and Reduce Negative Impacts of Climate Change. Sustainability. 2021; 13 (4):2269.

Chicago/Turabian Style

Takudzwa Mandizvo; Alfred Oduor Odindo; Jacob Mashilo. 2021. "Citron Watermelon Potential to Improve Crop Diversification and Reduce Negative Impacts of Climate Change." Sustainability 13, no. 4: 2269.

Original research article
Published: 17 February 2021 in Crop Science
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Recurrent drought is the main factor limiting groundnut yield, oil and fodder quality. Breeding and deployment of drought tolerant and high yielding genotypes with quality attributes is essential to meet the requirements of the food and feed sectors. The objective of this study was to determine drought tolerance, kernel and fodder yield and quality amongst diverse groundnut genotypes for direct production or breeding. Hundred genotypes were evaluated at the International Crops Research Institute for the Semi‐Arid Tropics (ICRISAT)/India during 2018/19 and 2019/20 under drought‐stressed (DS) and non‐stressed (NS) conditions using a 10×10 alpha lattice design with two replications. Data were collected on kernel yield (KY), oil content (OC), oil yield (OY), protein content (PC), palmitic acid content (PAC), stearic acid content (SAC), oleic acid content (OAC) and linoleic acid content (LAC), haulm yield (HY) and fodder quality parameters such as the contents of dry matter (DM), ash, nitrogen (NC), neutral detergent fiber (NDFDM), acid detergent fiber (ADFDM), acid detergent lignin (ADLDM), in vitro digestibility (IVOMD) and metabolizable energy (ME). Data were subjected to parametric and non‐parametric statistical analyses. Combined analysis of variance revealed significant (P< 0.05) genotype differences for all assessed traits. Genotype × water regime interaction effects were significant for KY, OC, ash, NC, NDFDM and ADLDM. Kernel yield positively and significantly (P<0.05) correlated with oil yield (r = 0.99), LAC (r = 0.13), ash (r = 0.32), NDFDM (r = 0.54) under DS condition. Haulm yield was positively and significantly (P<0.05) correlated with OC (r = 0.24), NDFDM (r = 0.19), ADFDM (r = 0.18) and ADLDM (r = 0.17) under DS condition. Cluster analysis grouped the test genotypes into 12 distinct genetic groups. The study identified four genotypes with high kernel and haulm yields, and six genotypes with high oleic acid content. Further, 10 genotypes were selected with relatively better drought tolerance. The selected genotypes are recommended for further breeding and variety release adapted to drought conditions. This article is protected by copyright. All rights reserved

ACS Style

Seltene Abadya; Hussein Shimelis; Janila Pasupuleti; Jacob Mashilo; Sunil Chaudhari; Surendra S. Manohar. Assessment of the genetic diversity of groundnut ( Arachis hypogaea L.) genotypes for kernel yield, oil and fodder quantity and quality under drought conditions. Crop Science 2021, 61, 1926 -1943.

AMA Style

Seltene Abadya, Hussein Shimelis, Janila Pasupuleti, Jacob Mashilo, Sunil Chaudhari, Surendra S. Manohar. Assessment of the genetic diversity of groundnut ( Arachis hypogaea L.) genotypes for kernel yield, oil and fodder quantity and quality under drought conditions. Crop Science. 2021; 61 (3):1926-1943.

Chicago/Turabian Style

Seltene Abadya; Hussein Shimelis; Janila Pasupuleti; Jacob Mashilo; Sunil Chaudhari; Surendra S. Manohar. 2021. "Assessment of the genetic diversity of groundnut ( Arachis hypogaea L.) genotypes for kernel yield, oil and fodder quantity and quality under drought conditions." Crop Science 61, no. 3: 1926-1943.

Preprint
Published: 12 January 2021
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Citron watermelon (Citrullus lanatus var. citroides) is an underexploited and under-researched crop species with potential to contribute to crop diversification in sub-Saharan Africa and beyond. The species is commonly cultivated in the drier parts of Southern Africa, mainly by smallholder farmers who maintain a wide range of landraces. Understanding the molecular and morpho-physiological basis for drought adaptation of Citron watermelon in these dry environments can aid in screening local germplasm, identification of suitable traits for crop improvement and improving food system resilience among smallholder farmers by adding to crop diversification. This paper reviews literature on drought adaptation of C. lanatus spp. (C3 xerophytes), using the systematic review approach. The review discusses; (i) the potential role of citron watermelon in adding to crop diversification, (ii) alternative food uses and potential by-products that can be processed from citron watermelon and (iii) the role of Sub-Saharan farmers as key actors in conserving citron watermelon germplasm and biodiversity. Finally, the review provides a summary of significant findings and identifies critical knowledge gaps for further research.

ACS Style

Takudzwa Mandizvo; Alfred Oduor Odindo; Jacob Mashilo. Citron Watermelon Potential to Improve Crop Diversification and Reduce Negative Impacts of Climate Change. 2021, 1 .

AMA Style

Takudzwa Mandizvo, Alfred Oduor Odindo, Jacob Mashilo. Citron Watermelon Potential to Improve Crop Diversification and Reduce Negative Impacts of Climate Change. . 2021; ():1.

Chicago/Turabian Style

Takudzwa Mandizvo; Alfred Oduor Odindo; Jacob Mashilo. 2021. "Citron Watermelon Potential to Improve Crop Diversification and Reduce Negative Impacts of Climate Change." , no. : 1.

Journal article
Published: 03 December 2020 in Plants
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The evaluation of root system architecture (RSA) development and the physiological responses of crop plants grown under water-limited conditions are of great importance. The purpose of this study was to examine the short-term variation of the morphological and physiological plasticity of Lagenaria siceraria genotypes under water deficit, evaluating the changes in the relationship between the root system architecture and leaf physiological responses. Bottle gourd genotypes were grown in rhizoboxes under well-watered and water deficit conditions. Significant genotype-water regime interactions were observed for several RSA traits and physiological parameters. Biplot analyses confirmed that the drought-tolerant genotypes (BG-48 and GC) showed a high net CO2 assimilation rate, stomatal conductance, transpiration rates with a smaller length, and a reduced root length density of second-order lateral roots, whereas the genotypes BG-67 and Osorno were identified as drought-sensitive and showed greater values for average root length and the density of second-order lateral roots. Consequently, a reduced length and density of lateral roots in bottle gourd should constitute a response to water deficit. The root traits studied here can be used to evaluate bottle gourd performance under novel water management strategies and as criteria for breeding selection.

ACS Style

Dinoclaudio Zacarias Rafael; Osvin Arriagada; Guillermo Toro; Jacob Mashilo; Freddy Mora-Poblete; Rodrigo Iván Contreras-Soto. Plasticity of the Root System Architecture and Leaf Gas Exchange Parameters Are Important for Maintaining Bottle Gourd Responses under Water Deficit. Plants 2020, 9, 1697 .

AMA Style

Dinoclaudio Zacarias Rafael, Osvin Arriagada, Guillermo Toro, Jacob Mashilo, Freddy Mora-Poblete, Rodrigo Iván Contreras-Soto. Plasticity of the Root System Architecture and Leaf Gas Exchange Parameters Are Important for Maintaining Bottle Gourd Responses under Water Deficit. Plants. 2020; 9 (12):1697.

Chicago/Turabian Style

Dinoclaudio Zacarias Rafael; Osvin Arriagada; Guillermo Toro; Jacob Mashilo; Freddy Mora-Poblete; Rodrigo Iván Contreras-Soto. 2020. "Plasticity of the Root System Architecture and Leaf Gas Exchange Parameters Are Important for Maintaining Bottle Gourd Responses under Water Deficit." Plants 9, no. 12: 1697.

Articles
Published: 21 September 2020 in Acta Agriculturae Scandinavica, Section B — Soil & Plant Science
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Assessing the genetic variation and relationships present in crop germplasm is a pre-requisite for parental selection and breeding. The objective of this study was to determine the genetic relationships present among selected heat and drought tolerant wheat genotypes using simple sequence repeat (SSR) markers, agronomic traits and grain quality parameters to select desirable parents for breeding. Twenty-four agronomically selected wheat genotypes sourced from the International Maize and Wheat Improvement Centre (CIMMYT)’s heat and drought tolerance nursery and four local check varieties were genotyped using 12 selected polymorphic SSR markers. The test genotypes were phenotyped using yield and yield-component traits, and grain protein content (GPC) under non-stressed (NS) and drought-stressed (DS) conditions. Expected heterozygosity mean value of 0.58 indicated moderate genetic diversity for breeding. The studied wheat genotypes were delineated into six genetic groups using cluster analysis. Significant genotypic differences were observed for agronomic traits and GPC under NS and DS conditions. Genetically unrelated breeding parents including LM02, LM13, LM23, LM41, LM44, LM71, LM73 and LM75 were selected for population development and breeding for enhanced grain yield and protein content under heat and drought-stressed environments.

ACS Style

Zamalotshwa Thungo; Hussein Shimelis; Alfred Odindo; Jacob Mashilo; Admire Shayanowako. Genetic relationship among selected heat and drought tolerant bread wheat genotypes using SSR markers, agronomic traits and grain protein content. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2020, 70, 1 -11.

AMA Style

Zamalotshwa Thungo, Hussein Shimelis, Alfred Odindo, Jacob Mashilo, Admire Shayanowako. Genetic relationship among selected heat and drought tolerant bread wheat genotypes using SSR markers, agronomic traits and grain protein content. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2020; 70 (7):1-11.

Chicago/Turabian Style

Zamalotshwa Thungo; Hussein Shimelis; Alfred Odindo; Jacob Mashilo; Admire Shayanowako. 2020. "Genetic relationship among selected heat and drought tolerant bread wheat genotypes using SSR markers, agronomic traits and grain protein content." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 70, no. 7: 1-11.

Research article
Published: 18 June 2020 in Journal of Crop Improvement
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Development of high-yielding dual-purpose sweetpotato (Ipomoea batatas [L.] Lam) genotypes is useful for cultivation in mixed crop-livestock farming systems. The objective of this study was to determine genotype-by-environment interaction (GEI) for storage root yield (SRY), vine yield (VY), root: vine ratio (RVR), total above-ground and below-ground biomass (TABGB) and root dry matter content (RDMC) among newly developed sweetpotato clones to select promising dual-purpose clones. Forty-five sweetpotato genotypes, of which 32 were newly developed candidate clones, were evaluated across six diverse environments in Rwanda. Additive main effects and multiplicative interaction (AMMI) and genotype and genotype-by-environment (GGE) biplot analyzes were used to analyze GEI. AMMI analysis revealed a relatively larger proportion of the GEI effect for SRY (31.21%), VY (37.17%), RVR (41.73%), TABGB (35.24%) and RDMC (36.23%) than for genotype and environmental effects, suggesting differential response of test genotypes across environments for the assessed traits. GGE-biplot analysis explained total variation of 72.98% for SRY, 83.26% for VY, 74.03% for RVR, 78.82% for TABGB and 56.78% for RDMC. Clone 21 with enhanced SRY and TABGB, and clone 42 for SRY had broad adaptation. For better VY, clone 733 was the best performer in environments E2 and E6 which are designated as mega-environment (MGE) 2, and clone 321 in E1, E3 and E4 (MGE 3). For RVR, clone 577 had best adaptation in E3, E4 and E5 (MGE 1), while clone 460 in E2 and E6 (MGE 2). Clones 42 and 381 were best performers for RDMC with specific adaptation in environments E3 and E1, respectively.

ACS Style

Placide Rukundo; Hussein Shimelis; Mark Laing; Jacob Mashilo. Genotype-by-environment interaction for dual-purpose traits in sweetpotato. Journal of Crop Improvement 2020, 34, 800 -823.

AMA Style

Placide Rukundo, Hussein Shimelis, Mark Laing, Jacob Mashilo. Genotype-by-environment interaction for dual-purpose traits in sweetpotato. Journal of Crop Improvement. 2020; 34 (6):800-823.

Chicago/Turabian Style

Placide Rukundo; Hussein Shimelis; Mark Laing; Jacob Mashilo. 2020. "Genotype-by-environment interaction for dual-purpose traits in sweetpotato." Journal of Crop Improvement 34, no. 6: 800-823.

Online first articles
Published: 26 May 2020 in South African Journal of Plant and Soil
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Development of wheat (Triticum aestivum L.) varieties with increased yield potentials that are adapted to drought and heat stresses requires genetically differentiated and complementary parents. The present study established genetic profiles of heat and drought tolerant wheat genotypes through SSR loci and agronomic traits for breeding. Fourteen candidate wheat genotypes selected from the International Maize and Wheat Improvement Centre (CIMMYT) and a local variety were genotyped using 10 diagnostic SSR markers. Further, the genotypes were evaluated for agronomic performance under non-stressed (NS) and drought-stressed (DS) conditions. The mean gene diversity of 0.75 confirmed genetic diversity of evaluated wheat genotypes. Analysis of molecular variance accounted for 75 and 25% of the variation within and among genotypes respectively. Significant differences were observed for assessed agronomic traits under NS and DS conditions. There were significant (p < 0.01) correlations between grain yield and plant height (r = -0.42) and spike length (r = 0.39) under DS conditions. Cluster analysis allocated test genotypes to three genetic groups and aided selection of genetically unrelated and high-yielding heat and drought tolerant genotypes such as SM04, SM19 and SM32. These are useful germplasm for developing breeding populations for improved yield gains.

ACS Style

Sonto Silindile Mkhabela; Hussein Shimelis; Jacob Mashilo. Genetic differentiation of selected drought and heat tolerant wheat genotypes using simple sequence repeat markers and agronomic traits. South African Journal of Plant and Soil 2020, 37, 211 -219.

AMA Style

Sonto Silindile Mkhabela, Hussein Shimelis, Jacob Mashilo. Genetic differentiation of selected drought and heat tolerant wheat genotypes using simple sequence repeat markers and agronomic traits. South African Journal of Plant and Soil. 2020; 37 (3):211-219.

Chicago/Turabian Style

Sonto Silindile Mkhabela; Hussein Shimelis; Jacob Mashilo. 2020. "Genetic differentiation of selected drought and heat tolerant wheat genotypes using simple sequence repeat markers and agronomic traits." South African Journal of Plant and Soil 37, no. 3: 211-219.

Articles
Published: 15 April 2020 in Acta Agriculturae Scandinavica, Section B — Soil & Plant Science
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ACS Style

Maletsema Alina Mofokeng; Jacob Mashilo; Paul Rantso; Hussein Shimelis. Genetic variation and genetic advance in cowpea based on yield and yield-related traits. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2020, 70, 381 -391.

AMA Style

Maletsema Alina Mofokeng, Jacob Mashilo, Paul Rantso, Hussein Shimelis. Genetic variation and genetic advance in cowpea based on yield and yield-related traits. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2020; 70 (5):381-391.

Chicago/Turabian Style

Maletsema Alina Mofokeng; Jacob Mashilo; Paul Rantso; Hussein Shimelis. 2020. "Genetic variation and genetic advance in cowpea based on yield and yield-related traits." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 70, no. 5: 381-391.

Articles
Published: 12 February 2020 in Acta Agriculturae Scandinavica, Section B — Soil & Plant Science
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Wheat genotypes with pre- and post-anthesis drought tolerance offer enhanced yield gains under water-limited environments. This study determined pre- and post-anthesis drought responses of selected bread wheat genotypes in order to identify and select candidate genotypes for breeding. Fifteen genetically differentiated wheat genotypes were evaluated under non-stressed (NS), pre-anthesis drought stress (PrADS) and post-anthesis drought stress (PoADS) in glasshouse (GH) and field (FLD) environments. Data were collected on agronomic and physiological traits including number of days to heading (DTH), days to maturity (DTM), plant height (PH), number of spikelet per spike (NSPS), number of kernels per spike (NKPS), thousand kernel weight (TKW), grain yield (GY) and canopy temperature (CT). Analysis of variance revealed significant effects of genotypes, environments and their interactions for studied traits. Weak and positive correlations were recorded between GY with PH (r = 0.47 and 0.32), NSPS (r = 0.37 and 0.52) and TKW (r = 0.30 and r = 0.20) under PrADS and PoADS conditions, respectively. Genotypes SMY-006, SMY-008, SMY-016, SMY-042 and SMY-044 were identified with pre- and post-anthesis drought tolerance and high yield potential and suitable yield-component traits. These are useful genetic stocks for breeding or cultivation in water-limited environments to improve yield gains.

ACS Style

Sibusiswangaye Yolanda Mdluli; Hussein Shimelis; Jacob Mashilo. Screening for pre- and post-anthesis drought responses in selected bread wheat (Triticum aestivum L.) genotypes. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 2020, 70, 272 -284.

AMA Style

Sibusiswangaye Yolanda Mdluli, Hussein Shimelis, Jacob Mashilo. Screening for pre- and post-anthesis drought responses in selected bread wheat (Triticum aestivum L.) genotypes. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science. 2020; 70 (4):272-284.

Chicago/Turabian Style

Sibusiswangaye Yolanda Mdluli; Hussein Shimelis; Jacob Mashilo. 2020. "Screening for pre- and post-anthesis drought responses in selected bread wheat (Triticum aestivum L.) genotypes." Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 70, no. 4: 272-284.

Journal article
Published: 07 February 2020 in Journal of Plant Physiology
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A reduction in photosynthesis results in a reduced CO2 assimilation rate and availability of carbohydrates essential for fruit growth and development. This study determined photosynthetic efficiency and photoprotection mechanisms within and outside leaf canopy positions in ‘Gem’ avocado orchards and their relationship with avocado fruit maturity. The study was conducted in a commercial orchard at Everdon Estate in KwaZulu-Natal, South Africa. A total of 15 eight-year-old avocado trees (cv. Gem) were selected in a completely randomised design with three replicates, with each replicate consisting of five trees. Data were collected bi-weekly on photosynthetic rate (A), effective quantum efficiency of photosystem II (ϕPSII), stomatal conductance (gs), transpiration rate (T), electron transport rate (ETR), minimum fluorescence (Fo’), maximum fluorescence (Fm’), variable fluorescence (Fv’), intrinsic water use efficiency (WUEi), instantaneous water use efficiency (WUEins), intercellular CO2 concentration (Ci) and photochemical quenching (qP) from full bloom to fruit physiological maturity (∼25 % dry matter content (DM)). The results showed that leaves from the outside position had higher A (29.46 mol CO2 m−2s-1); gs (0.078 mol CO2 m−2s-1); ΦPS II (0.32); and qP (0.52) compared to those within the canopy position with lower A (19.27 mol CO2 m−2s-1); gs (0.0037 mol CO2 m−2s-1); ΦPS II (0.044) and qP (0.075), respectively. Contrastingly, chlorophyll fluorescence and photoprotection parameters were higher within the canopy than on the outside, suggesting that the greater proportion of energy accumulated within the canopy was used for photoprotection other than photochemistry. Photosynthetic rate (A), gs, Ci, T, WUEi and WUEins, correlated significantly with mesocarp dry matter (DM), while all other parameters correlated poorly. The high photosynthetic efficiency of leaves from outside the canopy resulted in an average DM of 28.9 % compared to 26.9 % of fruit within the canopy. The present findings suggest that reduced photosynthetic efficiency of ‘Gem’ avocado within the canopy position does not compromise fruit DM by reserving more energy for photoprotection; however, it delays maturity by about two weeks.

ACS Style

Sabelo Shezi; Lembe Samukelo Magwaza; Jacob Mashilo; Samson Zeray Tesfay; Asanda Mditshwa. Photochemistry and photoprotection of ‘Gem’ avocado (Persea americana Mill.) leaves within and outside the canopy and the relationship with fruit maturity. Journal of Plant Physiology 2020, 246-247, 153130 .

AMA Style

Sabelo Shezi, Lembe Samukelo Magwaza, Jacob Mashilo, Samson Zeray Tesfay, Asanda Mditshwa. Photochemistry and photoprotection of ‘Gem’ avocado (Persea americana Mill.) leaves within and outside the canopy and the relationship with fruit maturity. Journal of Plant Physiology. 2020; 246-247 ():153130.

Chicago/Turabian Style

Sabelo Shezi; Lembe Samukelo Magwaza; Jacob Mashilo; Samson Zeray Tesfay; Asanda Mditshwa. 2020. "Photochemistry and photoprotection of ‘Gem’ avocado (Persea americana Mill.) leaves within and outside the canopy and the relationship with fruit maturity." Journal of Plant Physiology 246-247, no. : 153130.

Article
Published: 30 January 2020 in Euphytica
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High-yielding sorghum genotypes with farmer-preferred agronomic traits and durable anthracnose resistance are key drivers of productivity and adoption. The objective of this study was to determine combining ability effects and heterosis of selected sorghum lines for yield, yield-related traits, and anthracnose resistance, to identify superior parents and families for further selection and breeding. Nine selected sorghum genotypes with known resistance to anthracnose were crossed, using a 9 × 9 half-diallel mating design. Parents and F1 families were evaluated across two locations, using a randomized complete block design with three replications. Significant (P < 0.01) genotype, location, and genotype × location interaction effects were observed for most traits and anthracnose resistance, indicating mixed performances of the tested genotypes, allowing for further selection. General combining ability (GCA) and specific combining ability (SCA) effects were significant (P < 0.01) for most traits, including anthracnose resistance, indicating both additive and non-additive gene action underlying inheritance of the studied traits. Parental genotypes such as Bt-623, 210903, 234112, and 226057 showed positive and significant GCA effects for grain yield. Parents 74222, 214852, and 71708 showed negative and significant GCA for anthracnose resistance. The following families: Bt-623 × 210903, Bt-623 × 234112, Bt-623 × Chemeda, Bt-623 × Gemedi, 210903 × 234112, 210903 × 71708, 74222 × 234112, 74222 × 226057, 234112 × 71708, 226057 × 214852 and 226057 × 214852 expressing positive SCA effects for grain yield were identified. The following desirable families were selected: 174222 × 234112, Gemedi × 71708, Bt-623 × 234112, Bt-623 × Gemedi, 226057 × 71708, Chemeda × 71708, and Gemedi × 71708 with negative SCA effect and low anthracnose severity. These are useful sorghum populations for resistance breeding or direct production.

ACS Style

Girma Mengistu; Hussein Shimelis; Mark Laing; Dagnachew Lule; Jacob Mashilo. Combining ability and heterosis among sorghum (Sorghum bicolor [L.] Moench) lines for yield, yield-related traits, and anthracnose resistance in western Ethiopia. Euphytica 2020, 216, 1 -21.

AMA Style

Girma Mengistu, Hussein Shimelis, Mark Laing, Dagnachew Lule, Jacob Mashilo. Combining ability and heterosis among sorghum (Sorghum bicolor [L.] Moench) lines for yield, yield-related traits, and anthracnose resistance in western Ethiopia. Euphytica. 2020; 216 (2):1-21.

Chicago/Turabian Style

Girma Mengistu; Hussein Shimelis; Mark Laing; Dagnachew Lule; Jacob Mashilo. 2020. "Combining ability and heterosis among sorghum (Sorghum bicolor [L.] Moench) lines for yield, yield-related traits, and anthracnose resistance in western Ethiopia." Euphytica 216, no. 2: 1-21.

Journal article
Published: 29 January 2020 in Journal of Food Composition and Analysis
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Development of sweetpotato genotypes with enhanced nutritional composition is key to improve food and nutrition security and for industrial applications. The objective of this study was to determine the effect of genotype-by-environment interaction (GEI) on nutritional composition of sweetpotato clones to identify and select promising clones for large-scale production. Root dry matter content (RDMC), protein (Prot), β-carotene (β-car), iron (Fe), Zinc (Zn), starch (Star), sucrose (Suc), fructose (Fruc) and glucose (Gluc) contents were evaluated among 24 newly developed sweetpotato clones and one check variety across six diverse environments in southern Ethiopia using a 5 × 5 simple lattice design. Data was subjected to additive main effects and multiplicative interaction (AMMI) to estimate genotype (G), environment (E) and GEI effects. According to Gollob’s F-test and FR-test, four interactions principal component axis (IPCA) were significant (p ≤ 0.001) in the AMMI model for most traits, except glucose content where three and two IPCA’s were identified as significant by both tests. As a result, AMMI-4 was diagnosed for all traits, except glucose content where AMMI-2 was recommended. AMMI revealed significant (p ≤ 0.001) G, E and GEI effects on the studied nutritional traits. G explained 54 and 93 % of total variation for DRMC and β-car, respectively indicating these traits were less influenced by GEI effects. Larger E effects were observed for Prot (65 %), Fe (55 %) and Zn (64 %) while larger GEI effects were observed for Star (58 %), Fruc (77 %), Suc (50 %) and Gluc (56 %). Some of the newly-developed clones such as G5 (Ukrewe × Ogansagan-5), G6 (Resisto × Ejumula-7), G12 (Resisto × Temesgen-12), G13 (Resisto × Temesgen-14) and G22 (Ejumula × PIPI-19) with high RDMC (> 30 %), Prot (> 7 %), β-car (> 12 mg 100 g−1), Fe (> 2 mg 100 g−1), Zn (> 1 mg 100 g−1), Star (> 60 %), Fruc (> 4 %), Suc (>10 %) and Gluc (> 5 %) contents were selected for further evaluations for large-scale production, industrial use and and use in breeding programmes.

ACS Style

Fekadu Gurmu; Hussein Shimelis; Mark Laing; Jacob Mashilo. Genotype-by-environment interaction analysis of nutritional composition in newly-developed sweetpotato clones. Journal of Food Composition and Analysis 2020, 88, 103426 .

AMA Style

Fekadu Gurmu, Hussein Shimelis, Mark Laing, Jacob Mashilo. Genotype-by-environment interaction analysis of nutritional composition in newly-developed sweetpotato clones. Journal of Food Composition and Analysis. 2020; 88 ():103426.

Chicago/Turabian Style

Fekadu Gurmu; Hussein Shimelis; Mark Laing; Jacob Mashilo. 2020. "Genotype-by-environment interaction analysis of nutritional composition in newly-developed sweetpotato clones." Journal of Food Composition and Analysis 88, no. : 103426.

Review
Published: 24 January 2020 in Plant Breeding
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Tepary bean (Phaseolus acutifolius A. Gray) is a relatively higher drought‐tolerant crop than common bean (P. vulgaris), serving as genetic resource for food and genetic enhancement of related legumes. Tepary bean production is hampered by cultivation of low yielding and abiotic stress‐susceptible cultivars. Targeted selection of agronomic, physiological and biochemical traits that maximizes yield gains using Phaseolus gene pool is useful to develop stress‐tolerant and high‐performing genotypes. The objective of this review is to provide breeding progress made regarding tepary bean improvement for drought adaptation. Agronomic, physiological and biochemical traits utilized for selection of drought‐tolerant genotypes are highlighted. Genetic and genomic resources developed for tepary bean or closely related species such as common bean useful for genetic analysis and breeding are discussed. Opportunities and challenges to facilitate breeding of tepary bean genotypes with improved abiotic stress adaptation are highlighted. This will enable development of drought‐tolerant tepary bean genotypes targeting selection of agronomic, physiological and biochemical traits. Use of genetically related and complementary Phaseolus species and marker‐assisted selection method is key to developing drought‐tolerant genotypes.

ACS Style

Saul Eric Mwale; Hussein Shimelis; Paramu Mafongoya; Jacob Mashilo. Breeding tepary bean ( Phaseolus acutifolius ) for drought adaptation: A review. Plant Breeding 2020, 139, 821 -833.

AMA Style

Saul Eric Mwale, Hussein Shimelis, Paramu Mafongoya, Jacob Mashilo. Breeding tepary bean ( Phaseolus acutifolius ) for drought adaptation: A review. Plant Breeding. 2020; 139 (5):821-833.

Chicago/Turabian Style

Saul Eric Mwale; Hussein Shimelis; Paramu Mafongoya; Jacob Mashilo. 2020. "Breeding tepary bean ( Phaseolus acutifolius ) for drought adaptation: A review." Plant Breeding 139, no. 5: 821-833.

Plant environment interactions
Published: 01 January 2020 in Journal of Plant Interactions
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This study determined genotype-by-environment effect on grain quality among heat and drought tolerant bread wheat genotypes to select ideal genotypes for grain quality improvement. Gliadin (Gli), gluten (Glu), glutenin (Glut), gliadin: glutenin ratio (Gli: Glut ratio) and total protein content (TPC) were determined among 28 elite bread wheat genotypes under non-stressed and drought-stressed conditions. Additive main effect and multiplicative interaction and genotype and genotype-by-environment biplot were used for data analyses. Large genotypic effects were observed for Gli (55.42%), TPC (67.78%) and Gli: Glu ratio (49.77%), suggesting genotypic variation for these traits. High environmental influence of 89.65 and 89.06% were observed for Glu and Glut. Wheat genotypes LM03, LM22, LM23, LM41, LM44, LM60, LM62, LM71, LM73, LM71, LM85, LM90 and LM95 with high protein and protein-fractions and high levels of abiotic stress tolerance (i.e. heat and drought) were selected for breeding for high grain quality.

ACS Style

Zamalotshwa Thungo; Hussein Shimelis; Alfred Oduor Odindo; Jacob Mashilo. Genotype-by-environment effects on grain quality among heat and drought tolerant bread wheat (Triticum aestivum L.) genotypes. Journal of Plant Interactions 2020, 15, 83 -92.

AMA Style

Zamalotshwa Thungo, Hussein Shimelis, Alfred Oduor Odindo, Jacob Mashilo. Genotype-by-environment effects on grain quality among heat and drought tolerant bread wheat (Triticum aestivum L.) genotypes. Journal of Plant Interactions. 2020; 15 (1):83-92.

Chicago/Turabian Style

Zamalotshwa Thungo; Hussein Shimelis; Alfred Oduor Odindo; Jacob Mashilo. 2020. "Genotype-by-environment effects on grain quality among heat and drought tolerant bread wheat (Triticum aestivum L.) genotypes." Journal of Plant Interactions 15, no. 1: 83-92.