Analysis Of Genetic Makers In AG And Interspecific Hybrid Of Gossypium (Cotton)

The special character of glandless seed and glanded plant is the target character which can comprehensively utilize new varieties of cotton. Gossypium bickii from Australia had a propority which gossypol is not showed until the formation of the cotyledone.In order to transfer the useful traits of bickii into the cultivars and improve the economic returns, The amphidiploid was got from G.arboreum×G.bickii,then the some tri-specific hybrids were derived from (G.arboreum×G.bickif) ×G.hirstum, (G.arboreum×G.bickii) × G.barbandense in shan xi Agricultural university.Amphidiploid of (G.arboreum×G.bickii) and Tri-specific hybrids were analyzed by morphological character.cytology and molecular marker in this paper. The main results as followers:The restult of morphology showed: (1)Amphidiploid of (G.arboreum×G.bickii) had the same characters as G.arborewn and G.bickii.17.4%of characters came from G.arboreum such as the size of leaves, 26.1% from G.bickii such as the hairess of plant, 8.8% of characters was transgressive such as the colour of petal.(2)The hybrid of (G.arboreum×G.bickii)×G.hirstum had the same characters as G.arboreum, G.bickii and G.hirstum. 26.1 %of characters of the hybrid was from G.bickii such as the condition of embracing bell, 4.3% of characters came from G.arboreum such as the colour of anther,26.1 %of characters was from G.hirstum and G.arboreum such as the type of bract ,13%belong to transgressive characters such as the colour of petal.(3)The tri-hybrid of (G.arboreum×G.bickii) ×G.barbadense had the same characters as G.arboreum G.bickii and G.barbadense.13.0% characters was from G.bickii such as the number of anther,9% from G.barbadense such as the hairess of plant,34.8% from G.barbadense and G.arboreum such as the colour of anther, 13.0%of characters was superior to its parents such as the colour of petal.The result of cytology showed:The chromosome number of tri-species is 52.lt is the same as the number of amphidiploid of AG,G.hirsutum, G.barbadense But the structure of tri-species chromosome is different from parents. The karyotype foumula of tri-hybrid (G.arboreum×G.bickii) ×G.hirstum is 2n=4x=52=2M+44m(2SAT)+6sm(2SAT).the range of relative length is 6.12-2.56%,the range of arm ratios is 1.05-1.82,mean arm ratios is 1.35. The type of karyotype is 1B.The karyotype foumula of tri-hybrid (G.arboreum×G.bickii) ×G.barbadense is 2n=4x=52=44m(2SAT)+8sm(2SAT).the range of relative length is 6.91-1.99 %,the range of arm ratios is 1.01-2.31,mean arm ratios is 1.37.The type ofkaryotype is 2B.The analysis of RAPD showed :(1)A total of fifty DNA bands were amplified in amphidiploid.of them,7.8% DNA bands came from the specifical bands of G.arboreum,20.03% was from the spefical bands of G.bickii.(2)of the amplified bands in the hybrid of (G.arboreum × G.bickii) ×G.hirstum,l8.2% came from amphidiploid of AG,20.0%came from G.hirsiitton,the number of special bands is 6,the percentage of special bands is 10.9%. ?of the amplified bands in the hybrid of (G.arboreum×G.bickii) ×G.barbadense,l8.6%came from amplidiploid of AG,20.03%came from G.barbadense, the number of special bands is 6,the percentage of special bands is 10.2%.All of the results of morphology .cytology and molecular marker showed that the genetic substance of G.bickii had been transferred into amphidiploid of (G.arboreum×G.bickii),thegenetic substance of amphidiploid had been transferred into G.hirsiitian and G.barbadense, the tri-species of (G.arboreum×G.bickii) ×G.hirstum, and (G.arboreum×G.bickii) ×G.barbadense were truly tri-specific hybrids.