ISSR Marker Of Germplasm In Rice Of Long Panicle And Big Grain Character And Genetic Analysis On Yield-related Traits

According to the modern rice research, great achievement of rice breeding depends on the finding and effective using of special materials. 68 representative rice varieties was derived from IRRI new plant type strains, which with crossing and radiation methods. Selected 6 strains among them by using ISSR markers. According to partial diallel mating design, parents and F₁genetic generations derived from six long panicles big grains. Another partial diallel mating design, parents and F₁ genetic generations derived from six long panicles big grains and six R-line (Duoxi 1 hao, Miyang 46, Minghui86, Shuhui527, Shuihui838 and IR24) . Analysis on Addictive-dominance effect and interaction with environment genetic model and corresponding statistical methods in two different areas(Fuhzou and Shaxian), the genetic and correlation analysis was conducted about 13 traits of the two hybrid system. The results were showed as follow.1, Genetic diversity in 68 accessions was assessed using inter-simple sequence repeat (ISSR) markers. A total of 80 ISSR primers were screened, of which 9 polymorphic and informative patterns were selected to determine the genetic diversity and genetic relationships. Total of 70 bands were amplified, of which 47 were polymorphic (about 67．1%). The size of the bands ranged from 240-2000bp. Each primer with an average of 5．2 bands. All 68 accessions could be distinguished completely by ISSR markers. In summary. ISSR is a suitable and effective tool to evaluate genetic diversity among rice differential germplasms. According to the clustering results, all 68 collected accessions could be classified into 5 groups based on the genetic similarity (GS=0．72) . Of which 10 accessions were in the first group, the second group included 50 accessions, the third group included 5 accessions, while the fourth group has 2 accessions, the fifth group respectively. It was suggested that the cluster was significantly associated with the genetic races.2, The analysis on hybrid of long panicle and big grain with Addictive-dominance effect and interaction with environment genetic model indicated that among the yield and yield components traits, the traits of panicle length(PL), number of first branch(NFB), length of second branch(LSB), 1000-grain weight(1000GW), grain length(GL), grain width(GW) and grain thickness(GT) was mainly control by addictive effect, and the narrow heredity is higher, except length of second branch(LSB) and 1000-grain weight(1000GW), the other five traits not affected by addictive and environment interaction effect; the average of the spikelets of main panicle(NSMP), number of grains main panicle(NGMP), rate of seed setting(RSS), length of first branch(LFB), number of second branch(NSB) and grain weight per plant(GWPP) mainly affected by dominance effect, the others 12 traits mainly affected by dominance and environment interaction effect except the LFB.3, The result of hybrid of long panicle and big grain with R-line analysis showed that, all the 13 traits exist distinct addictive effect, 1000GW, panicle length, WL and WT, the rate of addictive /phenotype is 85．7%,79．4%,70．9%,58．2% respectively, the heritability in the narrow sense is higher, whereas addictive and environment interaction effect is lower. Amost traits have dominance and dominance and environment interaction effect. The hybrid generation synthesizes parents' eminent traits, and hope to be applied to the R-line improvement.