Study On The Physical And Chemical Characteristics, And RAPD Analysis Of Aphis Resistance In Melon Inbred-line "LZK-0402"

Several melon including four inbred-line and three cultivated varieties and eight F1 hybrids and one F2 off-spring were employed in this experiment to study the physical and chemical characteristics and the genetic characteristics of aphis resistance. The surface structure and the free amino acids content and the total nitrogen content and the soluble sugar content and the total phenols content in the leaves are analyze to study the mechanism of aphis resistance. RAPD Molecular markers are used to detect the linkege of aphid resistance gene through the analysis of F2 population. The results are as follows:1. 16 melon including four inbred-lines, three cultivated varieties, eight F1 hybrids,one F2 off-spring ,are investigated for their aphis resistance, the results show that the inbred-line of"LZK-0402"and eight F1 hybrids are resistance to aphid,"LZK-0201","LZK-0415","ZK3-10","huanghou","akesuhuangpi","huangsuixian"are susceptible to aphid; F2 offspring shows that resistance/ susceptibility basic matched 3:1 comparison of segregation. The results showe that the aphis resistant gene is controlled by single dominant gene.2. The trait of anti-aphid in inbred-line of"LZK-0402"has the relationship with the structure in the leaves of melon. The density of setae of different melon cultivars has a positive correlation (F=15.186, P=0.0176) .The regression equation is: Y=4.0329-0.0702X(R2=0.7915). the density of stomata of different melon cultivars has a positive correlation (F=16.6881 P=0.0150) .The regression equation is: Y=5.8553-0.094X (R2 =0.8067). Their showe that the higher pubescence density and stomata density was, the lower amount of the aphid on leaves of melon,the more resistance to aphid.3. The trait of anti-aphid in inbred-line of"LZK-0402"has a positive correlation with some free amino acids content in the leaves of melon. The regression equation is: Y=-2.869+36.969XTh(rF=732.9196 R=0.9986)。4,330 random sequence dicer-primer are used screen the RAPD markers linked to aphid resistance gene in the inbred lines of melon and their hybrid progenies F2.The results showe that one of these primer is conform to the requirements. And the length of the band of DNA is 1100bp,it is named OPA1100,the genetic distance is13.7 cM.