| چکیده انگلیسی مقاله |
Extended Abstract
Introduction: Oat, as a dual-purpose cereal, has an important role to provide human food and animal feed and fodder regarding to its high amounts of beta-glucan, protein, vitamins, minerals, fatty acids and valuable antioxidants. Oat breeding programs have been steadily decreasing compared to other cereals due to decrease in cultivated area. Therefore, identifying and studying sources of diversity in oats is critical and valuable regarding to release new cultivars with better quality and higher grain yield per unit area. Thus, this experiment was carried out with the aim of evaluating different genetic parameters and principal component analysis in order to determine the amount of genetic diversity in oat genotypes.
Materials and methods: In this study, 361 oat genotypes of seven species belong to 50 countries from five continents which were received from Australian Grain Genebank (AGG) and kept in the genebank of the Campus of Agriculture and Natural Resources, Razi University were investigated. Estimation of the genetic parameters related to plant height, panicle length, days to 50% flowering, days to 50% physiological maturity, biological yield, grain yield, straw yield, harvest index, thousand seed weight, number of seeds per panicle and number of panicle per square meter of the genotypes were performed. This experiment was conducted in a simple square lattice design with two replications under normal irrigation condition, in two cropping years 2017-2019 in the research farm of the Agriculture and Natural Resources Campus, Razi University, Kermanshah.
Results: Based on the results of the one-year variance analysis, there was a highly significant difference between genotypes regarding all the measured traits which indicates the presence of considerable genetic diversity between these genotypes. The results of mean comparison based on LSD method showed (NILE), (KENT), (LA PREVISION), (ZLATAK), SDO-185), OX87:080-2), (ACACIA), AND (DUNNART) genotypes had the highest grain yield for two years, while, Genotypes (LIGOWA), (NILE), (VENTURA), (YULAF), (NMO-712), (SDO-185), (VDO-931.1), (SLAVUGE), and (no.9278) had the highest mean for biomass in two cropping years. The results of the descriptive statistics showed the wide range of changes for the most of the investigated traits, as it was variable for grain yield from 56.30 to 789.81 g/m2 in the first year and from 39.59 to 627.28 g/m2 in the second year. Based on the results of correlation analysis, the most positive and significant phenotypic correlation was calculated between biological yield and straw yield in both years. The result of phenotypic and genotypic correlation also, showed a significant relationship between grain yield and all studied traits except plant height, panicle length, days to heading, and days to maturity in the first year. Also, it had a significant phenotypic correlation with all traits except plant height and straw yield in the second year. The traits of 1000- kernel weight, plant height, days to heading, and number of panicles per square meter had the highest genetic variance in both years. The range of general heritability in the first year was variable from 70.06 to 95.87%, respectively, for the traits of days to physiological maturity and 1000 seed weight, and in the second year, from 77.85 to 94.91% for biological yield and 1000 seed weight. Grain yield, biological yield, straw yield, number of panicles per square meter, and number of grains per panicle had a high percentage of heritability and genetic advance simultaneously. Based on the principal component analysis the first two main components explained 63.3 and 67.8 percent of the total changes in each year, respectively.
Conclusion: The results of variance analysis of the data obtained from this study indicated the existence of significant genetic diversity among the evaluated genotypes in terms of all measured traits, which can be attributed to the existence of different species with different geographical origins. Comparing the average data, genotypes 336, 349, 356 and 360 were introduced as the genotypes with the highest average grain yield in both years. Based on the results of Principal Component Analysis and Correlations Analysis, it can be found that the attributes of the number of panicles per square meter, the number of grains per panicle, 1000-kernel weight, and biological performance are very effective in breeding programs to achieve superior varieties. The genotypes NILE, LA PREVISION, OX87:080-2 and DUNNART were the superior genotypes in terms of the mentioned traits and grain yield. The estimation of genetic parameters showed that the selection based on the number of panicles per plot, the number of grains per panicle, and plant height plays a significant role in improving grain yield because of having a high broad heritability and significant genetic advance at the same time. According to the results of this study, it is possible to separate the superior genotypes in terms of grain yield and biological yield, and perform subsequent tests for grain and fodder genotypes, separately. Also, valuable traits for easier access to this important issue in subsequent oat improvement programs could be identified. |