Detection Of Mutation In Watermelon Induced By Space Flight And Clone Of Specific Fragment

Watermelon(Citrullus lanatus),originating in the African savannah,is a world horticultural crops.Because of its high food value and health value has been widely planted in China is to the advantage of the industry.However,the watermelon is very narrow genetic resources in the breeding of new varieties are largely limited.Space mutation breeding is an all-around new breeding technology which combines with mutation breeding and biotechnology,agricultural breeding technology,and it will be very broad prospects for application in plant breeding.In this study,200 individual plants of M₂ of the male parent of space mutation Jing xin No.1 were preserved by tissue culture technique as assisted measure and observed the morphologic differences.The mutations were detected by AFLP,and the fragments were cloned,sequenced and analyzed.The main results are as follows:1.The better method of the watermelon about pedicel tine disinfection:first,wash 30 min by flowing water;second,disinfect 10～15s by 75%alcohol;third,disinfect 10 min by 0.1%HgCl₂,then wash 4～5 times by asepsis water;the last,plant on the culture medium.The culture medium of the pedicel fine elongation is MS+0.2 mg/L KT.2.The asepsis- pedicel tines of watermelon were observed,the individual plant No.135 growed slower than the CK,speculated that it was mutate plant.3.DNA of 200 materials genome was amplified with 53 AFLP primer pairs;two fragments were detected by AFLP primer(E50/M60)on two single plants No.74 and No.135.No.135 had been validated as mutation from molecule level,and No.74 had been found as mutation too.4.The different fragments of No.74 and No.135 were recovered,cloned,sequenced.The length of different fragment of No.135 is 253 bp,and the two specific fragment size of No.74 were 81 bp and 98 bp.5.The different fragment of No.135 was extended by TAIL-PCR,and full length was 1379 bp.ESTs similarity analysis by BLASTx and BLASTn software showed that the EST was 93%identical to the mRNA sequence of Low-light stressed cucumber.