Heredity of fiber output at the intergenomic (A2 x C) cotton hybrids F1

Germplasm and Genetic Stocks

poster

Sirojidinov, Bekhzod

Sirojidinov, Bekhzod

The fiber is considered the basic product of cotton plant is inherited polygenecally along with other quantitative traits. The fiber output is related with following traits, as: fiber index, fiber length, fiber output, number of seeds per boll and 1000 seeds weight. Inheritance of the trait of fiber output at the interspecific hybrids F1 received at crossing of intraspecific varieties of the species G.arboreum L. (ssp. obtusifolium, ssp. obtusifolium var. indicum, ssp. perenne (Blanco) Mauer, ssp. nanking (Meyen) (with a brown and white fiber)) and Australian (G.australe F.Muell., G.nelsonii Fryx.) cotton species has been studied. It is necessary to notice that the intraspecific varieties of the species G.arboreum L. and Australian wild species on a fiber output strongly differ from each other. Average value of a fiber output basically make up 28,4-29,9%, except for subspecies ssp. obtusifolium at which the fiber output make up 20,5%. The Australian wild cotton species are characterized by low indicators of a fiber output. Average value of studied trait at them make up 6,0-6,5%. The analysis of results of a fiber output at the interspecific hybrids F1 has shown that the studied trait is inherited with a bias towards the best parent and average value of a fiber output has made up 11,4-25,2%. At hybrid combination F1 G.australe х G.arboreum ssp. obtusifolium the fiber output has made up 20,6%. The high amplitude of variability of a trait within 14,3-28,6% was noted. The domination coefficient was equal hp = 1,0 where dominant inheritance of the trait was observed. It is necessary to notice that the reciprocal combination of the given hybrid (F1 G.arboreum ssp. obtusifolium х G.australe) have appeared sterile, for definition of the reasons of sterility demands additional cytoem-bryological research. At the reciprocal hybrids F1 G.arboreum ssp. obtusifolium var. indicum х G.australe and G.australe х G.arboreum ssp. obtusifolium var. indicum the fiber output has made up 24,6-25,2%, the amplitude of variability was equal 16,7-31,3% and 20,0-28,6% accordingly. Intermediate inheritance of the trait (hp = 0,6 and hp = 0,5 accordingly) was observed. At the interspecific hybrids F1 received at crossing of the intraspecific varieties of the species G.arboreum L. with species G.nelsonii the intermediate inheritance of the trait with a bias towards the best parent was revealed basically. Thus, as a result of studying of the inheritance a fiber output at the interspecific hybrids F1 received at the crossing of the intraspecific varieties of an old-world cotton species G.arboreum L. and wild-growing Australian species, dominant and intermediate inheritance of a trait of «fiber output» was established. It is necessary to note that, the received interspecific hybrid combinations will enrich the cotton genepool and can be used in the further genetic and breeding research as the donors combining useful traits and properties of the Indochinese and Australian species.