Yield Stability and Adaptability of Elite Doubled Haploid (DH) Rice Genotypes in Different Locations in Central Clay Plains of the Sudan

Stability analysis of grain yield is an efficient tool for the selection of varieties adapted to fairly wide cultivation zone. A study aims to determine adaptability and stability for grain yield and agronomic performance of 10 elite Doubled Haploid (DH) rice genotypes generated through another culture technique, along with local cultivar Umgar as a check under irrigated lowland conditions in three different environments in the central clay plains of the Sudan;during two cropping seasons 2019 and 2020. The trials were conducted in a randomized complete block design with three replications. Grain yield stability was studied, using the Additive Main effect and Multiplicative Interaction (AMMI) model. Bi-plots were developed following GGE bi-plot methodology over the six environments. The combined analysis of variance revealed significant to highly significant (P < 0.001) effects of genotypes, environments, and genotype by environment interaction. Moreover, the analysis of variance based on AMMI indicated significant genotypes, environments, and GE interaction with a total variation of 43.16%, 44.26% and 12.58% respectively. A biplot-AMMI analysis and yield stability index incorporating the AMMI stability value and yield in a single non-parametric index were used to identify the genotypes with the highest and stable yield. The overall mean for grain yield was 5.69 t/ha, with a range of 5.77 to 4.12 t/ha. The genotypes k150147, k150870, k150032, k150912, and k150307 out yielded the local check Umgar by 40%, 38%, 34%, 34% and 33% respectively. The most genotypes were mid-early maturities which were harvested at 107, 113, 108, 109 and 112 days after sowing, respectively. These five genotypes also showed grain yield stability along with their high mean yield performance according to the AMMI analysis and widely adaptable to the tested locations. Therefore, the five out yielding genotypes will be considered for cultivation under irrigated system condition in central clay in the Sudan.

Genetic Diversity Analysis of Elite Doubled Haploid Rice Genotypes for Yield Attributing Traits in White Nile State, Sudan

The development of new rice varieties is highly dependent on genetic diversity in desirable agronomic traits. Therefore, this study aimed to identify potential genotypes having the characters of Korean varieties (Tongil-type) and japonica developed through doubled haploid (DH) technology to apply in our breeding materials. 35 elite DH lines derived from another culture of Korean and African rice along with two local checks were planted in a randomized complete block design with three replications during the two seasons of 2019 and 2020. All evaluated genotypes exhibited a wide and significant variation in the ten measured traits. The highest heritability related to high genetic advance was recorded for the number of tiller/plant, grain yield t/ha, number of filled grain per panicle, and thousand grain weights (g). Genotypic coefficient of variation and genetic advance were recorded for number of tiller/plant, number of filled grain per panicle, 1000 grain weight and grain yield t/ha in both seasons. Moreover, there was a highly significant and positive correlation of grain yield with number of filled grain per panicle (0.65), number of tiller/plant (0.64) and number of panicle per m2 (0.54). Cluster analysis based on grain yield components trait grouped the 37 rice genotypes into four clusters. Cluster B was the largest and consisted of 13 genotypes. Finally, it could be concluded that, based on number of productive tillers, number of filled grain/panicle, number of panicle per m2, and grain yield, the lines KF170506, KF170509, KF170542, KF170530, KF170543, KF170500 and KF170510 were high potential for further selection for new type of irrigated rice. In addition, hybridization of these 7 high-yielding could be used to achieve higher heterosis among the genotypes. Furthermore, this evaluation could be useful in developing reliable selection indices for improving rice breeding programs.