Huseyin Basal

Cottonseed oil and yield assessment via economic heterosis and heritability in intraspecific cotton populations

Due to the difficulty in producing cotton F 1 hybrid seed through hand emasculation and pollination, the capture of heterosis in cotton production is limited. The purpose of this study was to evaluate the potential of 6 × 6 F 1 and F 2 intra-hirsutum diallel hybrids relative to heterosis, inbreeding depression, heritability and correlation. Average F 1 hybrids mean values were higher than those of F 2 s, while F 2 s exceeded the parents. However, in F 1 s and F 2 s, the average mean values were 22.30 and 19.48 for seeds boll -1 , 8.87 and 8.56 g for seed index, 112.36 and 87.51 g for seedcotton yield and 30.07 and 28.30% for cottonseed oil. Heterosis over better parents was more pronounced in F 1 s as compared to F 2 s. However, in F 1 s and F 2 s, the average positive heterosis was 11.54 and 4.50%; 3.40 and 2.41%; 46.30 and 28.96% and 6.04 and 1.52%, respectively, for the above traits. Even after segregation and inbreeding depression, the F 2 s expressed about 50% of F 1 s heterosis. The inbreeding depression in F 2 s was -6.51 to -16.92 with low to high heritability, and significant positive correlation of cottonseed oil with other traits. The cultivar CIM-1100 derivatives performed better and exceeded all other hybrids in both generations. Key words: Hybrid vigor, inbreeding depression, cottonseed traits, cottonseed oil, Gossypium hirsutum .

COMPARISON OF MEAN YIELD COMPONENTS AND FIBER QUALITY PARAMETERS OF ADVANCED BULK GENERATIONS IN F2, F3 AND F4 INTERSPECIFIC AND INTRASPECIFIC COTTON POPULATIONS

The performance of interspecific and intraspecific cotton hybrid populations were compared to investigate the correlation among F2, F3 and F4 bulk generations in terms of yield, lint percentage, and fiber quality during 2009 to 2011. In addition to that, this research investigated the effect of combining abilities on hybrid performance at further generations. For this purpose, nine interspecific and six intraspecific hybrids with eight parents were evaluated under west part of Turkey (Aegean region) environmental conditions. With the generation progresses, the highest drop in fiber length and fiber strength was detected in interspecific duo to the inbreeding depression and genetic breakdown in advanced populations. Based on 15 tested hybrids, the observed mean yield and fiber quality in the F2 does not adequately predict the performance of hybrids in the F4 generation. Thus, selection of individual plants should be delayed until the F4 generation especially for interspecific hybrids, but individual plants would be selected at early generation in intraspecific hybrid populations. In the study it was found that a higher general combining ability (GCA) does not necessarily confer a higher specific combining ability (SCA) and that the GCA and SCA were independent of one another, and that in F4 high yielded hybrid population was obtained from cross which at least one parent of hybrid has maximum positive GCA effects. These results show that instead of use only one criteria, F2 performance for intraspecific hybrids and F3 performance for interspecific hybrids, low heterosis and inbreeding depression, combining ability of parents could be used together to determine the most promising hybrid populations to be used as a source for further selection.