| Improving salt tolerance and breeding salt-tolerance of rice induced by elicitor is environmentally-safe, economic and effective.On the basis that elicitor HI could improve salt-tolerance of R6, this study took R6, ZhanB, Boâ…¡B and 9311 as experimental materials. The morphological traits and physiological indexes of rice were determined with HI pretreatment under salt stress at the seedling stage.In this way, salt-tolerance rice varieties that couldn't be elicited by HI were identified and screened out. SSR was employed to estimate genetic similarity between R6 and ZhanB, Boâ…¡B, 9311. The optimal hybrid parent was defined to establish crossing populatio. This study also made genetic analysis of root length and preliminar molecular mark detection on F2 populaiton, which provided the basis for further study on mechanism of root enlongation of R6 induced by HI under salt stress. The main results were as follows:1.The impact of elicitors on different rice varieties in the seeding stage under salt stressR6,ZhanB, Boâ…¡Band 9311 seedlings were treated with 0.7% NaCl and HI-0.7% NaCl.Under 0.7% NaCl stress, four varieties all showed salt sensitive features such as the growth of roots were inhibited, leaf tips was wilted. The symptoms of R6 alleviated obviously induced by HI, roots were white and longer for example. While Zhan B, Boâ…¡B and 9311 had hardly changed contrast with the comparison pretreating by salt.Indexes of four rice varieties that physiology indexes were at the same level exsited difference after HI treatment under salt stress. HI could enhanced the activity of roots, reduced the content of MDA as well as the permeability of plasma membrane and increased the content of soluble sugar of R6, but the change of Zhan B,Boâ…¡B and 9311 treating by HI was not significant.Those indicated HI had selectivity in inducing anti-salt.Induced by HI in salt stress, four rice varieties which were all salt sensitive showed different salt-tolerance ability. HI could improve salt tolerance of R6 but it didin't affect salt tolerance of ZhanB, Boâ…¡B and 9311. 2.The genetic similarity analysis among four rice varieties and the selection of parent materialsBy detecting genomicDNA extracted using agarose, complete and clear DNA bands were observed. It showed the purity of DNA extracted was higher and was suitable for amplifying PCR.248 effective primer pairs were chosed from 257 pairs SSR molecular markers covering 12 chromosomes of rice .The result showed that the polymorphic primer pairs betweenR6 and9311,ZhanB,Boâ…¡Bwere 111, 59, 57respectively.The order of genetic similarity coefficient was 9311>ZhanB>Boâ…¡B. 9311 and R6 in relationship were fasthest. So 9311 could be selected as the salt senstive parent to establish crossing population with R6.Which would be a reference for further rice salt-tolerant mechanisms.3.The genetic analysis on root length of rice induced by HI under salt stressF2 population produced by the crossing of R6 and 9311 segregated in the significant growth of root length or not after HI pretreatment under salt stress. And the segregation ratio of long roots to short roots was 3:1 which indicated that the characteristic of root elongation might be controlled by one recessive gene.And the frequency distribution diagram shown as skew distribution, that showed the growth of rice root induced by HI may be controlled by one major gene. Under salt stress pretreated by HI, 111 pairs SSR primer were used to amplify 10 longest-root per plant and 10 shortest-root per plant respectively from F2 population which was produced by the crossing of R6 and 9311. The results showed that there was significant correlation between root length and specific fragment amplified by RM15861 with coefficient 0.52, which indicated there was correlation between primer RM15861 and the root elongation of R6 induced by HI.But the little tested population and incomplete genetic population may have some influence on the results.The group of plants detected was less and which need expand population for further exploration and study in future experiments.
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