Diallel analysis of boll weight in F1 intraspecific cotton hybrids (G. hirsutum L.)
Valentina Dimitrova, Minka Koleva, Ana Stoilova
Abstract: Cotton boll weight is one of the most important structural elements of the yield. The purpose of the study was to analyze the boll weight in F1 cotton hybrids and to clarify the genetic structure of this trait in view of the selection strategy and to lead an effective selection. The hybrid populations of two diallel combinations, each with 6 parental forms, were examined. An incomplete diallel scheme was used, including the parents and one set of crosses. It was found that for the inheritance of boll weight both additive and non-additive genetic effects were of importance, the manifestation of which depended on the diallel combination, it was also possible and the year conditions. Mainly non-additive gene effects were participated. It was found that for the inheritance of boll weight both additive and non-additive genetic effects were of importance, the manifestation of which depended on the diallel combination, it was also possible and the year conditions. Mainly non-additive gene effects were participated. The major groups of genes dominated to the trait increase, correlation coefficients rxp(Wr+Vr) between parent mean values and aggregate covariance-variance values were negative and medium-high to high.
Genetic variation, expressed through the coefficient of inheritance in narrow sense (h2), was low to moderate, and in view of the large dominance, the selection of this trait should be conducted in the later hybrids generation - F3-F4. Different types of inheritance were observed in individual crosses, those with positive overdominance predominated, showing heterosis more pronounced in the first diallel combination, and weaker in the second one. The heterosis effect reached up to 14.0% for the cross Barut × Darmies (Ist diallel combination) and 9.4% for the cross Rumi × Boyana (IInd diallel combination).
Genetic variation, expressed through the coefficient of inheritance in narrow sense (h2), was low to moderate, and in view of the large dominance, the selection of this trait should be conducted in the later hybrids generation - F3-F4. Different types of inheritance were observed in individual crosses, those with positive overdominance predominated, showing heterosis more pronounced in the first diallel combination, and weaker in the second one. The heterosis effect reached up to 14.0% for the cross Barut × Darmies (Ist diallel combination) and 9.4% for the cross Rumi × Boyana (IInd diallel combination).
Keywords: combining ability; cotton; G. hirsutum L.; genetic control
Date published: 2019-07-02
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