QTL Analysis Of Seed/grain Storability By Using Advanced Backcross Population In Rice(oryza Sativa L.)

Rice(Oryza sativa L.) is the most important cereal crop worldwide. Rice seed vigor/grain quality will begin to deteriorate in the second year when stored under the normal condition, which will result in large economic loss and put a threat to the food security. So a lot of manpower, material and financial resources had to been put into maintaining the seed vigor and grain quality. It will be of great significance to do research on seed/grain storability, to illuminate the mechanism underlying seed/grain quality deteriorateion, and help develop new cultivar with better storability.A BC3F8 population derived from a cross between Suyunuo(as recurrent parent) and Guichao 2(as non-recurrent parent) was used in this study. One hundred and nineteen pairs of SSR primer which had better polymorphism were selected to conduct the genetic linkage map, and the distance between the markers was 15~20c M. 12 traits were measured under natural and artificial aging treatment and cold storage conditions, respectively, i.e. seed vigor index consisting of germination momentum(GE), germination percetage(GP) and germination index(GI), and viscosity characteristics consisting of peak viscosity(PKV), hot viscosity(HPV), cool viscosity(CPV),breakdown value(BDV, =PKV-HPV), setback value(SBV, =CPV-PKV), consistency value(CSV, =CPV-HPV), paste temperature(Pa T) and peak time(Pe T), and free fatty acid value(FFAV). Data were analyzed using one-way ANOVA based on phenotypic and genotypic value. The main results are as follows:A total of 46 QTLs for seed vigor-related storability were identified, among them, 4 QTL, viz. q GM-3-4(-log10(P)=9.81) near RM6266 on chr.3, q GM-5-2(-log10(P)=9.64)near RM5796 on chr.5, q GM-5-4(-log10(P)=9.63)near RM6954 on chr.5, q GM-6-1(-log10(P)=9.59)near maker ch6.00239 on chr.6, explained phenotypic variations of 28.12%, respectively.A total of 116 QTLs for viscosity properties-related storability were identified, among them, 6 QTL, viz. q PKV-2-2(-log10(P)=8.75)near RM6318 on chr.2, q PKV-7-1(-log10(P)=8.79)near RM351 on chr.7, q PKV-11-2(-log10(P)=8.97) near RM287 on chr.11, q HPV-7-1(-log10(P)=7.6)near RM351 on chr.7, q SBV-7-1(-log10(P)=8.01)near RM351 on chr.7, q SBV-11-2(-log10(P)=7.96)near RM287 on chr.11, explained phenotypic variations of >30%, respectively.A total of 6 QTLs for FFAV-related storability were identified, among them, q FFAV-9-1(-log10(P)=3.55)near RM107 on chr.9 explained phenotypic variations of 12.06%.