Salt Tolerance Qingke Varieties (Lines) Screening And Rbcs Gene Cloning And Its Expression Analysis In Qingke (Huless Barley)

Land salinization is one of the problems for agricultural production. Meanwhile,with the deterioration of the ecological environment and unreasonable exploitation, makes this problem becomes more prominent. It has important significance for the development of modern agriculture and how to the use of large amounts of Saline land. Which screened excellent salt tolerance crop is one of the important measures to be cost-effective improvement of the saline land. Qingke as a specialty highland crop with a short growth period、soil fertility depletion small、but the yield is not low、besides which have relatively better salt tolerance. Screening and identification number of the salt tolerance barley varieties (lines), for saline land make improvements or research on the mechanism of salt tolerance of plants have more important role. Besides,from molecular biology to study the salt tolerance of plants is also a research focus, this will greatly enhance the ability to cultivate salt-tolerant crops with better rates. Based on this, in this study the salt resistance toward 34 accessions of qingke(hulless barley) cultivars (lines) from Tibet, Sichuan and Gansu of China was indentified were germination stage and seedling stage. At the same time, and may be related to salt tolerance rbcS gene was cloned and its expression were studied under salt stress conditions. The main results obtained are as follows:1. In this study, the salt resistance toward 34 accessions of qingke (hulless barley) cultivars (lines) from Tibet, Sichuan and Gansu of China was indentified by using germinative force, germination rate, germination index, germination vigor index, bud length and root length as indexes, during the germination stage. And also, comprehensively multi-indices evaluation on these qingke materials’tolerance to salt was carried out based on the correlation analysis, principal component analysis, subordinate function comprehensively analysis and cluster analysis. The results indicated that, the materials including XQ0478、Baiyuqingke、XQ0792、XQ0198 and N4-1 have relatively better salt tolerance, while Aiheiliu、Aliumi、9718 and 9803-2 have relatively weaker salt tolerance. In case of the synthetic evaluation value(D),the 34 qingke varieties (lines) were clustered into three groups:A, B and C.8 accessions of qingke materials,which have relatively better salt tolerance with D>0.5,clustered into Group A, while in Group B,4 entries of qingke varieties (lines) have relatively weaker salt tolerance with D<0.3. The remains including 22 accessions of qingke materials were clustered into Group C with D of 0.3≦D ≦0.5, implying that they have relatively moderately salt tolerance.2. The salt resistance toward 34 accessions of qingke (hulless barley) cultivars (lines) from Tibet, Sichuan and Gansu of China was indentified by using chlorophyll content、cell membrane permeability、SOD activity、MDA content、Na+/K+ ratio in leafs and Na+/K+ ratio in roots as indexes, during the seedling stage. And also, comprehensively multi-indices evaluation on these qingke materials tolerance to salt was carried out based on the correlation analysis, principal component analysis, subordinate function comprehensively analysis and cluster analysis. The results indicated that, the materials including Changmanghongsileng、Aiheiliu and XQ0391 have relatively better salt tolerance, while XQ0317、XQ0497 and XQ0491 have relatively weaker salt tolerance.In case of the synthetic evaluation value(D),the 34 qingke varieties (lines) were clustered into three groups:A, B and C.3 accessions of qingke materials,which have relatively better salt tolerance with D≧0.6, clustered into Group A, while in Group B,18 entries of qingke varieties (lines) have relatively moderately salt tolerance with 0.44≦D<0.6. The remains including 13 accessions of qingke materials were clustered into Group C with D of D<0.44, implying that they have relatively weaker salt tolerance.Meanwhile, the results of germination stage was compared with seedling stage was further analyzed. The results showed there are 11 accessions of qingke exhibit the same salt tolerance and are others materials exhibit different salt tolerance in the 34 accessions of qingke at the germination stage and seedling stage.3. According to known Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Small Subunit conserved sequences of barley and wheat to degenerate primers and amplified a DNA sequence and a cDNA sequences of rbcS gene in barley meterial.After sequencing and BLAST analysis showed:compare DNA and cDNA sequences were found to contain an intron length of 107bp in the DNA sequence. With rbcS gene sequences of qingke were comparing homologous sequences of other species and found the genetic relationship is closest with wheat and barley of rbcS gene and homology can reach 96.57% and 91.0%, respectively; the genetic relationship is farthest with potatoe and tomato and homology can reach 59.12% and 57.12, respectively.4. Using real-time quantitative PCR analysis the expression of rbcS gene at the different times under salt stress conditions of qingke material. The results show:rbcS gene expression was suppressed when the qingke is subjected of salinity stress, Especially when subjected to salt stress 12h its expression levels there are significant decline relative to the control group. In addition, observed the control group found light conditions for the rbcS gene expression is a significant regulatory role.