Yield Stability of Different Elite Wheat Lines under Drought and Irrigated Environments using AMMI and GGE Biplots

Wheat is the principal winter crop in Nepal. Drought affects 44% of the lands of the total wheat area in the country with a yield loss of 15–20%. This research focuses to minimize this loss through the identification of high-yielding lines stable across the drought stress and irrigated environments. The experiment was conducted in Alpha Lattice Design with 20 genotypes replicated twice with five blocks per replication from November 2019 to April 2020. The findings showed that genotypes, environments, and genotype-environment interaction have a highly significant effect on grain yield and explained 28.95%, 52.57%, and 18.47% of variation on yield, respectively. The which-won-where model revealed elite line NL 1420 is the most responsive line in the drought environment, followed by BL 4407, while elite line NL 1179 is the most stable line in irrigated environment. The mean vs stability model with principal component 1 and 2 explaining 65.76% and 34.24% respectively, showed that elite line NL 1420, BL 4407, BL 4919, Bhrikuti are both high yielding and stable lines while line NL 1179, Gautam, and NL 1384 are less stable in both test environments. Similarly, the ranking genotypes model indicated lines close to the ideal line are NL 1420, BL 4407, BL 4919, Bhrikuti as the most representative line for genotype evaluation. Thus, elite wheat line NL 1420 and NL 1179 are recommended as specifically adapted to drought and irrigated environments, respectively, and elite line NL 1420, BL 4407, BL 4919, Bhrikuti are recommended for further evaluation for stability. Int. J. Appl. Sci. Biotechnol. Vol 9(2): 98-106

Estimating Elephant-Grass Adaptability and Stability for Energy-Biomass Production by Regression Models

In Brazil, elephant grass has been researched for energy generation, as it represents an alternative energy source by virtue of its biomass production. The present study was developed to examine the adaptability and energy-biomass production stability of 73 elephant-grass genotypes under a biannual-harvest regime, using the methodologies proposed by Eberhart and Russell and Cruz. The experiment was carried out at the northern region of Rio de Janeiro State, Brazil. Nine harvests and subsequent evaluations were performed at six-month intervals. Each harvest was considered an environment of genotype evaluation. After the plants were harvested, their dry matter yield (DMY) was estimated in t ha-1 harvest. Combined analysis of variance revealed highly significant effects of genotypes, harvests, and genotype × harvest interaction, by the F test. In five of the nine evaluated harvests, the genotypes had an average dry matter yield greater than the overall mean. The method of Eberhart and Russel was effective in identifying highly adaptable elephant-grass genotypes with high dry matter production stability throughout the nine harvests. When the method of Cruz was used, no genotypes were found comprising high yielding ability, adaptability to unfavorable environments, responsiveness to environmental improvement, and high stability altogether.

Estimations of fibre trait stability and type of inheritance in cotton

Traits affecting fibre quality were evaluated in a multi-location environmental experiment. Four main cotton regions in Greece were selected as different environments. Five commercial cotton cultivars were used for evaluation of 10 fibre quality traits. Each cultivar was sown in 10 different fields in each region. Environmental fluctuations within regions affected each quality trait differently showing a different degree of inheritance. Four traits showed the lowest stability index values indicating quantitative inheritance, further four traits with intermediate values indicated determination by a few genes, while the more stable and thus with qualitative inheritance traits were considered to indicate fibre maturity and uniformity. The mean estimation of stability in multi-location experiments was found the same as in multi-genotype evaluation. Two cultivars (Elsa and Celia) were found to be more stable across the Greek environments and two regions favoured stability for almost all traits. Correlations between regions were high and the same was found between genotypes.

Evaluation of neck blast resistance and agronomical performances on double haploid rice population in greenhouse and endemic field

Windarsih G, Utami DW. 2017. Evaluation of neck blast resistance and agronomical performances on double haploid rice population in greenhouse and endemic field. Nusantara Bioscience 9: 371-377. Blast disease caused by fungal Pyricularia grisea Sacc. is one of the most destructive diseases of rice in the world. The development of blast-resistant rice varieties will be essential to control this disease. This research aimed (i) to compare the resistance response to neck-blast among DH lines from double cross IR54/Parekaligolara//Bio110/Markuti and the differential varieties against three selected Indonesian blast races in greenhouse, (ii) to identify the gene(s) that caused the resistance to neck-blast based on the association between the resistance response and the genotype evaluation using molecular markers linked to Pi1, Pi33, Pib, Pir4 and Pir7 genes, and (iii) to evaluate the resistance response to leaf and neck blast on DH lines in endemic field (Sukabumi) and the agronomical performance of selected DH lines in optimum field in Ciasem of Subang, West Java, Indonesia during December 2013 to March 2014. Eleven double haploid lines from double-crossing IR54/Parekaligolara//Bio110/Markuti, the differential varieties as resistant control and the US2 variety for susceptible control were observed for neck-blast resistance response to three blast races in greenhouse and endemic field (Sukabumi), while the agronomical performances were observed in field of Ciasem-Subang. The results based on the genotyping evaluation, leaf and neck blast resistance, either in greenhouse and endemic location, and the agronomical performance in field showed that 5 selected double haploid lines had leaf and neck blast resistance and good performance on field trial. Thus they are promising for use either for further testing forwarding into releasing variety or used as donor for further blast resistant breeding activities.

GENOTYPE BY ENVIRONMENT INTERACTION AND GRAIN YIELD STABILITY OF ETHIOPIAN WHITE LUPIN (LUPINUS ALBUS L.) LANDRACES

SUMMARYGenotype by environment interaction is a common phenomenon in crop production and remains an important issue in genotype evaluation and recommendation. However, no detailed multi-environment evaluation of Ethiopian white lupin has been undertaken so far. Thus, this study was undertaken with the objectives to evaluate the performance and stability of white lupin landraces in six locations; and characterize white lupin growing environments in Ethiopia. Twelve white lupin landrace collections of Ethiopia were evaluated across six different locations in Ethiopia during the 2014/15 main growing season using a randomized complete block design with four replications. The genotype main effect plus genotype by environment interaction (GGE) biplots analysis was used to visualize the patterns of the interaction components. The results depicted that the tested landraces had differential performances across locations implying the presence of crossover interaction. The first two principal components (PC1 = 41.6% and PC2 = 21.8%) of the GGE explained 63.4% of the GGE sum of squares. All test locations were found to be representative with different degrees of reliability whereby Finote Selam and Dibate were found to be most representative. In addition, all test locations, except Mandura and Injibara, had generally similar and good discriminating power. Finote Selam and Dibate were found to be the most representative and discriminating environments and are characterized as most desirable test locations for white lupin improvement in northwestern Ethiopia. G2 was found to be the highest yielding and most stable landrace across the test environments, and hence identified as most desirable genotype recommended for production.