Evaluation Of Salt Tolerance In Barley And Screening Of Germplasm With High Salt Tolerance

Barley (Hordeum vulgare L.) is the world’s fourth largest cereal grain crop and classified into food barley, feeding barley and malting barley according to the application. Due to the characteristics of drought enduring, moisture resistance, barren tolerance, saline tolerance, precocity and so on, barley is widely planted in the world. Large area of diked tidal flats needs to be exploited in Jiangsu province. In order to speed up the development of these coastal tidal flats and improve the production efficiency of the winter crop, it is necessary to strengthen the identification and selection of barley salt-tolerant germplasm as well as the breeding of high yield and good quality barley varieties with salt-tolerant trait. In the present study, a natural population containing 95 barley varieties and a DH population containing 107 lines derived from Gairdner/CM72 were used to identify the salt tolerance in salt shoal field and green house. The effects of salt on main characters were analyzed and germplasm with high salt tolerance were screened by cluster method. Following are the main results:1. A natural population consisting of 95 barley varieties from different origin were used to evaluated of salt tolerance in seedling stage under the condition of nutrient solution and in field. Results of salt-tolerance in seedling stage indicated that root length, tiller number, green leaf number, dry weight of stem and dry weight of root were significantly decreased under the condition of salt treatment and different sources of germplasm had significant hereditary difference in salt tolerance. Principal component analysis indicated that the traits judging salt tolerance in seedling stage could be divided into three principal components, which were the culm-leaf characters, root traits and plant type and the contribution rate reached 81.97%. Based on the dynamic clustering and comprehensive assessment of the salt tolerance of natural population in seedling stage used three principal components as indexes,95 barley varieties were clustered into high resistance, medium resistance and sensitive three types, among which,36 barley varieties were germplasms with high resistance. The results of identification of the plant salt resistance cultivated in Dongxin farm, Lian yun gang, Jiangsu province in 2012 and 2013 showed that the differences of five plant traits among varieties reached significant level and four traits in addition to the grain weight per plant reached significant level in different years and in the interactions between years and varieties. Principal component analysis indicated that the plant traits determining salt tolerance were divided into two principal components which were surviving plant rate and ear-kernel characters with the cumulative contribution of 85.44% and 93.43%, respectively. Based on dynamic clustering of plant salt tolerance and the total appraisement value on account of membership function used two principal components as index,95 barley varieties were divided into high resistance, medium resistance and sensitive three types and the number of high tolerance barley germplasms were 20,19 in 2012 and 2013, respectively. Integrating the results of two years, four high resistant lines were selected. Furthermore, three barley germplasms showed good salt tolerance both in seedling stage and field combined with the identification results.2. According to the salt-tolerance identification of DH population constructed by Gairdner/CM72 hybrid F1 pollen planted in Dongxi farm, Lian yun gang, and Jinhai farm, Yan cheng and the investigation of 7 traits that were plant height, ear length, internode length below spike, panicles per plant, seeds number per plant, the total weight of per plant and thousand seed weight, the results showed that, the differences of 7 traits among DH lines and between DH lines and locations reached significant or extremely significant level. Moreover, in addition to the grain weight per plant, the differences of the rest 6 traits reached significant level among locations. Principal component analysis showed that the salt tolerance of plants in filed was divided into Plant-type traits and yield traits, and the contribution rate reached 80.6572% and 85.7331%, respectively. Based on dynamic clustering of plant salt tolerance and the total appraisement value on account of membership function used two principal components as index,107 barley varieties were divided into high resistance, medium resistance and sensitive three types. Among which,31 and 37 high-resistant barley strains were selected in Lian yun gang and Yan cheng, respectively. Integrating the results of two locations,15 high-resistant strains with stable performance were selected. Furthermore, salt tolerant parent CM72 was classified as high resistance type in two locations and sensitive parent Gairdner was classified as sensitive type in two locations. This showed that results of the present study were relatively reliable.