Expression Of Gland Formation And Fine Mapping Of Dominant Glandless Gene Gl₂^e In Cotton

Cotton is one of the economic and oil crops in the world which can not only provide excellent natural fiber, but also has a long widely planted history. The gossypol can play an important role in avoiding the harm of pests and diseases by improving defense responses owing to the gossypol which is stored in pigment glands,however on account of toxicity, nutrition can not be well used by humans.Recently researchers pay a attention to Dominant glandless gene Gl2 e.The synthesis of pigment glands is generally influenced by Gene Gl2 e.,in addition it can prevent the disadvantageous effects due to character segregation compared with that controlled by the recessive genes. Therefore,the study of gene Gl2 e becomes important research domain and primary direction and thinking in the low gossypol cotton breeding progressively.In this research,in order to the fine mapping of purposegene, the two hybridization parents were composed by the two materials gland Jing55263 and glandless Suwu070.Two F2 populations were build which is named A contains 1628 individuals respectively andthe other which is named B contains 280 plants.There are 416 gland plants, 813 low-gland plants and 399 glandless plants in F2 populations named A. The number of three gland characters are 81,131 and 68 in the other population.The result Chi-squareanalysof A populationsis 0.35 and the other is 2.32.The separation ratio of the gland character which emerged proportion of 1:2:1 in the two F2 populations which is named A and B coincided with segregation law. At the same time we find out that the Dominant glandless was controlled by one pair of incomplete dominance gene.During germination of cotton,we find that the vitality of POD and CAT and SOD elevated. We alsomake a conclusion that the vitality of PODand CAT and SOD of Jing55263 is much higher than that in Suwu070.In this research we adopt Affymetrix gene chip to reveal features of cotton gland development. The number of different expression genes is 741,there are 403 genes up-regulated and the number of down-regulated genes is 238 among these genes.Except some unknown function genes,these genes include two kinds of categories relevant.At first there are some genes which is related to photosynthesis、signal transducer and organ development.Afterwards there are transcription factors which can play an important role in metabolic process and organ development and other genes involve in stress expression and metabolic process such as lipid、protein、amino acids and hormone.Among them, 4 genes which significantly express in the gossypol and the phenypranoid pathway have been further confirmed with RT-PCR and the results were in accordance with the Genechip’s data.At first the gene Gl2 e was rough mapped between SSR marker HAU1321 and NAU2251. Genetic distance between Gl2 e and NAU2251 a is 0.94 c M and Genetic distance between Gl2 e and HAU1321 is 5.10 c M.This result provided a foundation of fine mapping and map-based cloning of Gl2 e gene in preliminary mapping. In line of early research, taking into account the G.arboreum(A genome) sequence data,the new SSRmarkers in the candidate region of gene Gl2 ewhich were developed can help us to find out the closely linked markers with purpose gene. On the basic of early conclusion, the population which contains 1628 plants was used to find the recombinant plants was used tofor the gene Gl2 e.By detecting these recombinants plants, the gene Gl2 e was mapped between mark HG13 and HG21, genetic distance between Gl2 e and HG13 is 0.26 c M and Genetic distance between Gl2 e and HG21 is 0.15 c M.The biological process of gene which contrals the synthesis of gossypolaremetabolic process, organ development,regulation of transcription.