Cassava (Manihot esculenta Crantz) was introduced to Southeast Asia in the 16th–17th centuries and has since flourished as an industrial crop. Since the 1980s, Thailand has emerged as the leading producer and exporter of cassava products. This growth coincided with the initiation of cassava breeding programs in collaboration with the International Center for Tropical Agriculture (CIAT), focusing on root yield and starch production. The success of Thai cassava breeding programs can be attributed to the incorporation of valuable genetic diversity from international germplasm resources to cross with the local landraces, which has become the genetic foundation of many Thai commercial varieties. Effective evaluation under diverse environmental conditions has led to the release of varieties with high yield stability. A notable success is the development of Kasetsart 50. However, extreme climate change poses significant challenges, including abiotic and biotic stresses that threaten cassava root yield and starch content, leading to a potential decline in starch-based industries. Future directions for cassava breeding must include hybrid development, marker-assisted recurrent breeding, and gene editing, along with high-throughput phenotyping and flower induction. These strategies are essential to achieve breeding objectives focused on drought tolerance and disease resistance, especially for CMD and CBSD.

Background and Objective: Flowering locus T (FT) genes are involved in the flower induction mechanism in plants as florigen signals. The objective of this study was to study the relationship between the expression of Flowering locus T genes (MeFTs) in cassava and flowering traits under the different flowering induction conditions. Materials and Methods: The experimental design for flowering induction was RCBD for 4 replications. There were 5 treatment factors which were control, red light set from 5 pm to 7 am, 0.5 mM 6-benzyladenine (BA) with 2 mM silver thio-sulfate (STS), paclobutrazol for 6 g/plant and potassium chlorate (KCIO3) for 250 g/plant. The number of plants with flower bunches and the average number of bunches per plant in two cassava varieties were collected each month from 5-9 months after planting (MAP). The leaf samples were collected from HB80 and R9 varieties at 5-7 MAP for RNA extraction to study MeFT1 and MeFT2 expression. Results: The results show that MeFT1 expression level positively correlated with flowering traits in the same month, while MeFT2 expression level positively correlated with flowering traits in the following months. Conclusion: Therefore, expression of MeFT2 can be used for the prediction of cassava flowering in the following month which will assist the breeder for the crossing management.

Social Impact Statement: Cassava is a vital food source for millions worldwide, crucial for food security and economic stability. This study analyzed cell wall polysaccharides in cassava roots to understand their impact on cooking properties. We found these polysaccharides influence the textural attributes of cassava roots, essential for both cooking and consumption. The research highlights the need to further identify and analyze cassava cell wall components. By improving our understanding of these components, we can improve food security, affordability, and resilience in diverse regions, ultimately contributing to global food security and better aligning with consumer preferences.Summary: The textural attributes of cassava roots significantly influence preferences in cooking and consumption as a food source, yet the specific components dictating these properties remain unclear. We aimed to identify the factors shaping the cooking properties of cassava roots. We conducted a compositional analysis of 22 traits in a diverse F1 biparental population derived from soft‐ and hard‐boiling progenitors. The traits encompassed cooking qualities, starch properties, and cell wall composition. Specific cell wall components including cellulose, xylan, un‐esterified, and methyl‐esterified homogalacturonan (HG) demonstrated a correlation with cooking quality attributes: sensory assessments related to texture (SAT) and water absorption during boiling (WAB). Correlation and regression analyses revealed that these wall components collectively contribute to 20% of SAT variability and 14% of WAB variability. SAT appeared to be influenced by methyl‐esterified and un‐esterified HGs, xylan, and cellulose, impacting the tensile strength of the cell wall. Conversely, WAB appeared to be associated with methyl‐esterified HG, potentially altering water absorption properties. Although genome‐wide association studies (GWAS) were unable to identify significant SNPs for SAT and WAB, notable associations emerged for cellulose, xylan, and un‐esterified‐ and methyl‐esterified HG. Candidate genes associated with these SNPs point towards diverse cell wall‐related proteins, transcription factors, sugar metabolism‐related genes, and glycosyl hydrolases. This study provides insights into the relationship between cassava root compositions and cooking characteristics and the role of wall components in determining the cooking quality of edible cassava. This information represents a substantial contribution towards the development of protocols for selecting varieties with texture preferences.

Grafting of cassava (Manihot esculenta Crantz) understocks with scions from Manihot glaziovii was proposed to improve the cassava root yield and as a temporal approach to overcoming the problem of cassava mosaic disease (CMD). This work compared performance of nongrafted KU50 with M. esculenta grafted as understock with M. glaziovii, KU50 or HB80 scions. KU50 and HB80 are released M. esculenta varieties. Work was conducted in the field using a randomized complete block design (RCBD) with four replicates in two seasons (rainy and dry seasons) in Thailand. The M. glaziovii grafted plants were larger than nongrafted controls. Grafting also increased fresh root yield by 25% (dry season) and 37% (rainy season) and dry matter content by 19% (dry season) and 42% (rainy season) over the nongrafted controls. Net photosynthesis (P_n), stomatal conductance (g_s) and growth parameters indicated that the grafted plants had a higher photosynthetic capacity and more vigorous growth than nongrafted controls during the dry season. Correlation coefficients of P_n and g_s with growth and productivity parameters at different ages of the plant were highly significant during the dry season but not in the rainy season. This study demonstrated that M. glaziovii–cassava grafting improved cassava growth and root yield.

Background and Objective: Breeding between highland and lowland rice varieties is one of the strategic breeding of lowland rice for enhancing drought-tolerant capacity through root structure improvement. The objective of this study was to evaluate the phenotypic diversity of rice root traits in pot screening compared to the lowland parent. Materials and Methods: The basket method was utilized in pot cultivation to evaluate the 100 of F7 Recombinant Inbred Lines (RILs) derived through single seed descent method from a cross between lowland rice, RD49 variety and upland rice, Payaleumgaeng (PLG) variety. The two parents and F7 progenies were evaluated for the number of shallow roots (SRN) and the number of deep roots (DRN), together with other traits which were the number of total roots (TRN), the Ratio of Deep Rooting (RDR), maximum Root Length (RL), Root Dry Weight (RDW), Shoot Dry Weight (SDW), the ratio of Root to Shoot Weight (RSR) and Plant Height (PH). Results: The result showed that PLG had significantly higher SRN, DRN, TRN and RDR than RD49. The distribution of these traits showed slightly positive skewness in DRN, RDR, RDW, SDW and RSR and negative skewness in SRN, TRN, RL and PH. However, some lines in this RIL population displayed better performance of root traits compared to both parents. Principal Component Analysis (PCA) of DRN, SRN, TRN and RDR in this population showed a distinctly different pattern among both parents. Most of the selected lines had superior RDR over RD49 and had various root characteristics patterns due to the diverse PCA coordinates. The yield trial of some breeding lines in this cross show superior yield over RD49 under drought-prone cultivation area. Conclusion: This study showed broad phenotypic diversity in the population constructed through single seed descent selection for enhancing deep root structure in rice for drought adaptation.

1. Cassava (Manihot esculenta Crantz) is a cornerstone crop for food security and income across the tropics and subtropics, and it also underpins a large and growing starch-processing economy. Its ...