Summary: Abscisic acid (ABA) is a major phytohormone involved in important stress‐related and developmental plant processes. Recent phosphoproteomic analyses revealed a large set of ABA‐triggered phosphoproteins as putative mitogen‐activated protein kinase (MAPK) targets, although the evidence for MAPKs involved in ABA signalling is still scarce. Here, we identified and reconstituted in vivo a complete ABA‐activated MAPK cascade, composed of the MAP3Ks MAP3K17/18, the MAP2K MKK3 and the four C group MAPKs MPK1/2/7/14. In planta, we show that ABA activation of MPK7 is blocked in mkk3‐1 and map3k17mapk3k18 plants. Coherently, both mutants exhibit hypersensitivity to ABA and altered expression of a set of ABA‐dependent genes. A genetic analysis further reveals that this MAPK cascade is activated by the PYR/PYL/RCAR‐SnRK2‐PP2C ABA core signalling module through protein synthesis of the MAP3Ks, unveiling an atypical mechanism for MAPK activation in eukaryotes. Our work provides evidence for a role of an ABA‐induced MAPK pathway in plant stress signalling.

Heat stress is a major limiting factor for crop productivity. Tomato is highly sensitive to heat stress, which can result in a total yield loss. To adapt to current and future heat stress, there is a dire need to develop heat tolerant cultivars. Here, we review recent attempts to improve screening for heat tolerance and to exploit genetic and genomic resources in tomatoes. We provide key factors related to phenotyping environments and traits (morphological, physiological, and metabolic) to be considered to identify and breed thermo-tolerant genotypes. There is significant variability in tomato germplasm that can be harnessed to breed for thermo-tolerance. Based on our review, we propose that the use of advanced backcross populations and chromosome segments substitution lines is the best means to exploit variability for heat tolerance in non-cultivated tomato species. We applied a meta quantitative trait loci (MQTL) analysis on data from four mapping experiments to co-localize QTL associated with heat tolerance traits (e.g., pollen viability, number of pollen, number of flowers, style protrusion, style length). The analysis revealed 13 MQTL of which 11 were composed of a cluster of QTL. Overall, there was a reduction of about 1.5-fold in the confidence interval (CI) of the MQTL (31.82 cM) compared to the average CI of individual QTL (47.4 cM). This confidence interval is still large and additional mapping resolution approaches such as association mapping and multi-parent linkage mapping are needed. Further investigations are required to decipher the genetic architecture of heat tolerance surrogate traits in tomatoes. Genomic selection and new breeding techniques including genome editing and speed breeding hold promise to fast-track development of improved heat tolerance and other farmer- and consumer-preferred traits in tomatoes.

Background The success of crop varieties introduction is tightly linked to the uses, biophysical conditions, the cropping systems in which the crop is integrated and farmers’ and consumers’ preferences. In Benin, however, pigeonpea production systems including the cropping systems, marketing, utilizations and preferences have received little attention. This study aimed at analyzing farmers’ practices and constraints related to pigeonpea production as well as identifying farmers’ preferred traits in pigeonpea. Methods The study was conducted in three pigeonpea-growing agroecological zones in Benin. Participatory rural appraisal tools including individual interview (n = 302) and group discussion were used to collect information on production system, constraints and preferred traits. Fisher’s exact test was used to assess the relationship between crop associated with pigeonpea and the growing areas. Based on preferred traits, villages were clustered using UPGMA. Results Pigeonpea is predominantly grown by men. Approximately 98% of the pigeonpea growers associated pigeonpea with other crops, while 2% of them grew the crop in pure stand. Pigeonpea grown in association with maize (48.7%) was the most encountered cropping system. The type of crops associated with pigeonpea depended on the growing area (P < 0.001), and a high diversity in crops combination was observed in the Department of Couffo. Lack of improved varieties, low productivity and lack of quality seed were major factors constraining pigeonpea production. The pigeonpea seed system was essentially informal with self-saved seed (79%), purchase from fellow farmers or from local markets (12%) and gift/exchange (9%) as seeds sources. Farmers’ preferences traits varied across pigeonpea-growing area, but overall, high yielding, early maturing, and resistance to pod borers were the main reported preferred traits. Conclusion Our results confirm the importance of pigeonpea both in the cropping systems and in contributing to ensure food security in the growing areas in Benin. Farmers’ varietal preferences were identified. This information is important for designing appropriate strategies for sustainable pigeonpea production. Insight gained into farmers’ preferred traits in pigeonpea varieties will also help in the choice of varieties or advanced breeding materials to be integrated into participatory varietal selection programs in order to improve productivity of the crop in Benin.

Cassava green mite [CGM, Mononychellus tanajoa (Bondar)] is a dry‐season pest that usually feeds on the underside of young leaves causing leaf chlorosis, stunted growth, and root yield reduction by 80%. Since cassava (Manihot esculenta Crantz) leaves and roots serve as a primary staple food source, a decline in cassava yield can lead to household food, nutrition, and income insecurity. To evaluate the existence of CGM resistance alleles in the available germplasm, a diversity panel of 845 advanced breeding lines obtained from IITA, CIAT, and the National Root Crops Research Institute (NRCRI) were evaluated for CGM severity (CGMS), leaf pubescence (LP), leaf retention (LR), stay green, shoot tip compactness, and shoot tip size. A genome‐wide association mapping detected 35 single‐nucleotide polymorphisms (SNPs) markers significantly associated with CGMS, LP, and LR on chromosome 8. Colocalization of the most significant SNP associated with CGMS, LP, and LR on chromosome 8 is possibly an indication of pleiotropy or the presence of closely linked genes that regulate these traits. Seventeen candidate genes were found to be associated to CGM resistance. These candidate genes were subdivided into seven categories according to their protein structure namely, Zn finger, pentatricopeptide, MYB, MADS, homeodomain, trichome birefringence‐related protein, and ethylene‐responsive transcription factor genes. This study revealed significant loci associated with CGM, not previously reported, which together represent potential sources for the ongoing effort to develop multiple pest‐ and disease‐resistant cassava cultivars.

Understanding factors driving farmers’ uses of crop genetic resources is a key component not only to design appropriate conservation strategies but also to promote sustainable production. However, in Benin, limited information is available on farmers’ knowledge related to pigeonpea uses and conservation. This study aimed at i) identifying and investigating the different uses of pigeonpea in relation with socio-cultural factors, namely age, gender, ethnic group and respondents’ residence, ii) assessing pigeonpea varieties richness at household level and iii) evaluating the extent and distribution of pigeonpea varieties. Three hundred and two farmers were surveyed using structured questionnaire. Direct observation, field visit and focus group discussion were carried out. Association between number of varieties maintained at household level and socio-cultural variables was tested. Mann-Whitney test was used to assess whether the number of varieties held by households headed by men and women were different. Distribution and extent of diversity was assessed through four cells analysis. Farmers in Benin mainly grow pigeonpea for its grains for home consumption. Pigeonpea’s stem and leaves are used for medicinal purposes to treat malaria, dizziness, measles, and eye infection. The ethnic group and the locality of residence of farmers influenced on the use of pigeonpea for medicinal purposes (P < 0.01). There was no significant association (P > 0.05) between the number of varieties held by household and the age of the respondent, number of years of experience in pigeonpea cultivation, the size of household, number of family members engaged in agricultural activities and gender. Farmers used criteria including seed colors, seed size, plant height, maturity groups and cooking time to classify their varieties. Varieties with white seed coat color were the most grown while varieties with black, red or mottled seed coat color are being abandoned and deserve to be conserved. Knowledge on medicinal uses of pigeonpea is vertically transmitted within community and pigeonpea varieties maintenance at household level does not depend on socio-cultural factors. This study will contribute to raise awareness on the various utilization of pigeonpea. In addition, it provides the basis for designing conservation strategies of pigeonpea genetic resources.