Correlation Between Relative Gene Expression Patterns of Two Flowering locus T (MeFT1 and MeFT2) in Cassava Leaf and Flowering Traits Under Different Flowering Induction Conditions.

<b>Background and Objective:</b> <i>Flowering locus T</i> (<i>FT</i>) 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 <i>Flowering locus T</i> genes (<i>MeFTs</i>) in cassava and flowering traits under the different flowering induction conditions. <b>Materials and Methods:</b> 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 <i>MeFT1</i> and <i>MeFT2</i> expression. <b>Results:</b> The results show that <i>MeFT1</i> expression level positively correlated with flowering traits in the same month, while <i>MeFT2</i> expression level positively correlated with flowering traits in the following months. <b>Conclusion:</b> Therefore, expression of <i>MeFT2</i> can be used for the prediction of cassava flowering in the following month which will assist the breeder for the crossing management.

Genome-wide association mapping and genomic prediction of yield-related traits and starch pasting properties in cassava.

KEY MESSAGE: GWAS identified eight yield-related, peak starch type of waxy and wild-type starch and 21 starch pasting property-related traits (QTLs). Prediction ability of eight GS models resulted in low to high predictability, depending on trait, heritability, and genetic architecture. Cassava is both a food and an industrial crop in Africa, South America, and Asia, but knowledge of the genes that control yield and starch pasting properties remains limited. We carried out a genome-wide association study to clarify the molecular mechanisms underlying these traits and to explore marker-based breeding approaches. We estimated the predictive ability of genomic selection (GS) using parametric, semi-parametric, and nonparametric GS models with a panel of 276 cassava genotypes from Thai Tapioca Development Institute, International Center for Tropical Agriculture, International Institute of Tropical Agriculture, and other breeding programs. The cassava panel was genotyped via genotyping-by-sequencing, and 89,934 single-nucleotide polymorphism (SNP) markers were identified. A total of 31 SNPs associated with yield, starch type, and starch properties traits were detected by the fixed and random model circulating probability unification (FarmCPU), Bayesian-information and linkage-disequilibrium iteratively nested keyway and compressed mixed linear model, respectively. GS models were developed, and forward predictabilities using all the prediction methods resulted in values of - 0.001-0.71 for the four yield-related traits and 0.33-0.82 for the seven starch pasting property traits. This study provides additional insight into the genetic architecture of these important traits for the development of markers that could be used in cassava breeding programs.

Phenotypic Diversity of Root Characteristics in Recombinant Inbred Lines of Cross Between Lowland and Highland Rice Varieties for Drought Tolerance Potential.

<b>Background and Objective:</b> 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. <b>Materials and Methods:</b> 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). <b>Results:</b> 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. <b>Conclusion:</b> 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.

Comparison of Grain Processing Techniques on Saponin Content and Nutritional Value of Quinoa (Chenopodium quinoa Cv. Yellow Pang-da) Grain.

<b>Background and Objective:</b> Quinoa grain contained saponin in pericarp, which causes bitter flavor. After harvesting, quinoa grain is required to remove saponin before being consumed. Thus, this study aimed to study post harvest management of grain processing on the saponin and nutrition value of quinoa grain. <b>Materials and Methods:</b> The experiment was arranged in a Completely Randomized Design (CRD) with three replications and saponin removal technique with milling process (T₁-T₂) and reagent washing (T₃-T₈) were used as experimental treatments comparing with non-process grains as a control (T₉). Nutrition analysis was an indication of quality in post-process quinoa grain. <b>Results:</b> The experiment found that T₁, T₃, T₄, T₅, T₆ and T₇ could reduce saponin content significantly different from T₉, while T₂ and T₈ still show high saponin content when compared with T₉. T₂ and T₄ techniques could maintain most of the nutritional value of quinoa grain when compared with control (T₉). <b>Conclusion:</b> Finally, this experiment could be concluded that quinoa was washed by alkaline solution (pH 8) for 8 min by three times (T₄) could be an optimum of saponin removal technique. This technique not only removed saponin but could also maintain quinoa grain qualities. Meanwhile, it potentially reduced for 66.03 percent of saponins content when compared with control treatment, which did not change in protein content, flavonoid content, moisture content, starch content, phenolic content and color (L*) of quinoa grain.

Cassava breeding and agronomy in Asia: 50 years of history and future directions.

In Asia, cassava (Manihot esculenta) is cultivated by more than 8 million farmers, driving the rural economy of many countries. The International Center for Tropical Agriculture (CIAT), in partnership with national agricultural research institutes (NARIs), instigated breeding and agronomic research in Asia, 1983. The breeding program has successfully released high-yielding cultivars resulting in an average yield increase from 13.0 t ha-1 in 1996 to 21.3 t ha-1 in 2016, with significant economic benefits. Following the success in increasing yields, cassava breeding has turned its focus to higher-value traits, such as waxy cassava, to reach new market niches. More recently, building resistance to invasive pests and diseases has become a top priority due to the emergent threat of cassava mosaic disease (CMD). The agronomic research involves driving profitability with advanced technologies focusing on better agronomic management practices thereby maintaining sustainable production systems. Remote sensing technologies are being tested for trait discovery and large-scale field evaluation of cassava. In summary, cassava breeding in Asia is driven by a combination of food and market demand with technological innovations to increase the productivity. Further, exploration in the potential of data-driven agriculture is needed to empower researchers and producers for sustainable advancement.