Document Type : Research Paper
Authors
1
Assistant Professor of Agricultural and Horticultural Science Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization, Mashhad, 91769-83641, Ir
2
Agricultural and Horticultural Science Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization, Mashhad, 91769-83641, Iran.
3
Researcher of Horticulture Crop Research Department, Khorasan Razavi Agricultural and Natural Resources Resaerch and Education Center, AREEO, Mashhad, Iran.
4
Assistant Professor of Plant Breeding Department, Cotton Research Institute of Iran, Agricultural Research, Education and Extension Organization, Gorgan, 49166-85915, Iran.
10.22092/ijcr.2024.365722.1214
Abstract
Background and objectives: Diverse plant genetic materials are potential treasures that are considered valuable support for plant breeding programs, because the plant breeding research is based on wide genetic diversity, and basically, without diversity, breeding and selection will have no meaning. This study was conducted to evaluate the diversity of different cotton landraces and identify the traits affecting their yield.
Materials and methods: In this study, 44 landraces of cotton were cultivated in the agricultural research station of Kashmir during the two years of 2018 and 2019. The traits of the number of open and closed bolls, crown diameter, crop yield, boll weight, number of monopodial and sympodial branches, plant height, and crop maturity were measured. Descriptive statistics, trait × genotype (GT) biplot analysis, factor analysis, and cluster analysis were used to investigate the objectives of this research. Statistical analyzes were performed based on the average of two-year data. In analyzing of descriptive statistics, JUMP software was used, SPSS 21 software was used for factor analysis and cluster analysis, and GEA-R software was used for GT biplot analysis. Results: Based on the average of two-year data, the range of boll weight and the number of closed bolls were high, which indicates the diversity of the investigated genotypes for the mentioned traits. Comparison between genotypes based on multiple traits made it possible to distinguish different genotypic groups. Cluster analysis of studied traits classified the genotypes into four main groups. The first group obtained from cluster analysis was earlier, but had the lowest average plant height, the number of monopodial and sympodial branches, the number of open bolls, and crown diameter. On the other hand, the second and third groups had the lowest amount of earliness. The genotypes of the second group had the lowest boll weight, the number of shoot branches, and the crown diameter, and the third group had the highest plant height, the number of branches, and the number of open bolls. The genotypes of the forth group had the highest earliness and the number of closed bolls. In order to increase earliness and reduced the plant height, the selection of genotypes from the first group for breeding programs can be helpful in obtaining cultivars with greater tolerance to environmental stresses, including drought. It is also possible to use the genotypes of the third group with the highest number of open bolls to cross with the genotypes of the first group in order to create quality and early cultivars.
Conclusions: There was considerable genetic diversity among the studied landraces in terms of most of the evaluated traits, indicating high potential for improving these traits through targeted selection in the breeding programs. The boll weight was the most important factor affecting the yield of cotton, and the fiber component had a greater effect on the boll weight of some studied genotypes than the seed component.
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