Development Of Monosomic Alien Addition Lines Of Gossypiumhirsutum-gossypium Anomalum

G.canomalum(2n = 2x = 26,Br)is a diploid wild cotton species which mainly distributed in dry coastal belt in Angola and South-West Africa and the southern borders of the Great Desert Belt.G.anomalum has many valuable genes such as good strength and fineness fibre,water deficit tolerance,resistances to pests and diseases,cytoplasm male sterile and so on,which can be introgressed into G.hirsutum L,the main cultivated cotton species to broaden its genetic basis,to enrichits genetic resources,improve its quality traits and to enhance its resistantance.Therefore,to systematically analyze the genetic effects of G.anomalum in the background of G.hirsutum at the chromosome level,we developed and constructed monosomic alien addition lines which only carried one chromosome of G.anomalum in G.hirsutum background by the combination of SSR markers and molecular cytogenetic techniques along with morphological survey.The results are as follows:(1)According to the tetraploid cotton genetic map builded by our lab,we selected 1402 pairs of markers on the D subgenome chromosomes to screen a set of G.hirsutum-G.anomalum alien addition lines polymorphic primers.Finally we got a total of 452 pairs of polymorphic primers and then,removed the dense clusters and selected only one marker at an interval of 10 cM,we ultimately gained 170 pairs codominant primers to genotype the G.hirsutum-G.anomalum alien addition lines.These codominant primers were evenly distributed on 13 chromosomes of D subgenome in G.hirsutum.(2)Simultaneously applying two labelled probes from G.anomalum and G.herbaceum genome DNA to improve GISH technology,we identified 108 MAALs which contained 52 chromosomes from G.hirsutum and one chromosome from G.anomalum.(3)Using SSR markers to identify 108 MAALs isolated,we found 11 MAALs,namely,MAAL-2Ba,MAAL-3Ba,MAAL-4Ba,MAAL-6Ba,MAAL-7Ba,MAAL-8Ba,MAAL-9Ba,MAAL-10Ba,MAAL-11Ba,MAAL-12Ba and MAAL-13Ba.There were still two MAALs(MAAL-1Baand MAAL-5Ba)remained not to be isolated,which were in the form of multiple additional lines.We also found that 10Ba chromosome had highest chromosome transmission rate,accounting for the largest proportion of about 31.5%in all the MAALs,followed by MAAL-4Ba and MAAL-6Ba which were both approximately 16.0%,MAAL-13Ba and MAAL-2B3 both were approximately 9.0%,MAAL-3Ba and MAAL-9Ba only had one plant with the low chromosome transfer rate.(4)These MAALs were observed by morphological traits and they all had specific traits.The outstanding traitis of MAAL-6Ba were its long style and stigma and light brown fibers,which all were derived from the parental diploid G.nomalum;MAAL-7Ba was the only MAAL which had purple floral spot but with slow growth rate;The flowers and bracts of MAAL-8Ba were very small as well as its less number of anthers than other MAALs,and its leaf color was deeper than two parents and other MAALs,whose chlorophyll content is relatively high;MAAL-10Ba showed the smallest leaves,flowers and boll and had more fruiting branches;MAAL-11Ba had big flowers withlarge number of anthers;the boll of MAAL-12Ba was very long the same as its carpopodium;the boll of MAAL-13Ba was big and round.Thus these unique traits may could be as morphological markers for easily distinguishing from each other between MAALs.(5)On the yield and quality traits,MAAL-9Ba exhibited the highest average boll weight,reached 5.49g,closed to the 5.64g of TM-1,but its lint percentage was 34.14%which was higher than the 28.16%of TM-1;MAAL-10Ba had the lowest boll weight,only 2.30g and itslint percentage was also as low as 29.46%.(6)After testing the fiber quality of 6 MAALs we found that the fiber length of these MAALs ranged from 25.84 to 27.99mm,being shorter than that of TM-1.The fiber micronaire of MAAL-8Ba was 4.04 which reached A grade of fiber quality;thoungh the fiber of MAAL-10Ba was as short as25.94mm,its fiber strengrthwas as high as 35.67cN/tex:the fiber strength of MAAL-8Ba also reached 32.44 cN/tex,higher than 31.95 cN/tex of TM-1.Overall these 11 MAALs we developed all had its distinct traits and potential excellent characteristics which could be used to introgress genes into G.hirsutum,thus they provided a good intermediate material in the aspect of improving the yield,fiber quality,pest and disease resistance of’ G.hirsutum.These 11 MAALs would be of important significance for high yield and quality,disease and insect resistance in breeding.