Creation And Molecular Genetical Identification Of The Beneficial Mutants In Upland Cotton (Gossypium Hirsutum L.)

Three varieties of upland cotton(Gossypium hirsutum L.),which are G-20,N-156 and NK-20,were induced by three methods including EMS chemical mutation,¹⁴N heavy ions implantation and ⁶⁰Coγ-rays radiation to select botany character,yield trait and fiber quality trait mutants.The acquirement of these mutants will be valuable not only for enriching the germplasm resources but also to the foundation of mutation material foreground for the location and clone of correlative genes.The main results were as followings:1.Brown colored fiber mutant named N-156 EMS M1-LBF had been selected by 1.5% Ethyl Methane-sulfonate(EMS) treated with germinating seeds.Brown colored fibre was controlled by one pair alleles through genetical analysis(one white colored:two light-brown colored:one deep brown colored).Fibre color correlated with fiber quality negatively.The fiber length(FL) changed shorter,fiber strength(FS) changed lower,fiber micronaire(FM) changed larger and fiber elongation(FE) changed higher along with fiber color deeping.The genetical diversity between mutant and CK was verified by the result of SSR polymorphic diversity comparison.2.Super-okra leaf,gossypol glandless mutant was obtained on M₂ generation by 250 Gy ⁶⁰Coγrays radiation to cotton varety NK-2.It was approved that super-okra leaf was incomplete dominance to normal leaf.Gossypol gland was controlled by one pair of recessive genes and heredity independent with leaf shape genes.The genotype of the mutant is L°L°glgl.The genetical diversity of mutant and NK-2 were checked by SSR polymorphic diversity comparison3.The seeds of variety G-20 were induced by 0.5%EMS.Two mutants named M₄-66-4 and M₄-236-5 were obtained on M4 generation through pedigree selection.The result of phenotype measurement indicated:FL and FS of M₄-66-4 were 26.85 mm and 24.80 cN/tex which were 1.99mm shorter and 1.90 cN/tex lower than that of G-20,meanwhile FL and FS of M₄-236-5 were 30.44 mm and 30.00 cN/tex which were 1.87mm longer and 3.30 cN/tex higher than that of G-20.The phenotype measurement of M_4:5 family lines were stable.The result of the SSR polymorphic diversity comparison to G-20 indicated:six SSR primers screened from 60 primer pairs correlated with FL and 52 primer pairs correlated with FS could amplify 33 polymorphic bands among mutants and G-20.The genetical stability and the variance among two mutants and G-20 were verified by the result of SSR polymorphic diversity comparison.4.Zygotes of variety G-20 were implanted by 0.125%EMS.Seed index(SI) of Zygote induced M₃-4-2,which had been selected on M₂ generation through pedigree selection, was13.12g,3.61g heavier than that of G-20.The phenotype measurement of M_3:4 family line was stable.The seeds of variety G-20 were induced by 0.5%EMS and the SI of M₄-97-2-4 was 6.80g,4.08g lower than that of G-20.SI of M_4:5 famliy line was stable.The result of SSR polymorphic diversity comparison to G-20 indicated:two SSR primers screened from 17 primer pairs correlated with SI,which were JESPR114 and CIR354, could amplify polymorphic bands among mutants and G-20.The genetical stability and the variance among two mutants and G-20 were verified by the result of SSR polymorphic diversity comparison.5.The seeds of variety N-156 were induced by 1.5%EMS.N-156 M₄-101-3 were obtained on M₄ generation through pedigree selection.The result of phenotype measurement indicated:FL,FS and FM of the:mutant were 30.28 mm,31.20 cN/tex and 4.86 which were 1.38 mm longer and 1.10 cN/tex higher and 1,03 thicker than that of N-156.The phenotype measurement of FL,FS and FM of M_4:5 family line were stable. The seeds of variety N-156 were implanted by ¹⁴N heavy ions.¹⁴N-156 M₃-100-4 was obtained on M₃ generation through pedigree selection.The result of phenotype measurement indicated:FL,LS and FM of ¹⁴N-156 M₃-100-4 were 27.42 mm,23.70 cN/tex and 5.13 which are 1.48mm shorter and 6.40 cN/tex lower and 1.30 thicker than that of N-156.The phenotype of FL,FS and FM of M_4:5 family line were stable.The genetical stability of FL,FS and FM were verified by the above results.The result of SSR polymorphic diversity comparison to N-156 indicated:five SSR primers screened from 60 primer pairs correlated with FL,52 primer pairs correlated with FS,42 primer pairs correlated with FM,which were BNL2821,BNL3280,BNL4030,BNL1513 and TMG8, could amplify 16 polymorphic bands among mutants and N-156.The result of FL,FS and FM of the two mutants on M₄ generation was verified by the variance statistics and DNA marker analysis in M_4:5 family line.The genetical stability and the variance among two mutants and N-156 were verified by the result of SSR polymorphic diversity comparison.