Studies On The Salt-tolerance Of Neo-tuberosum In Potato

Potato is sensitive to salt, and salt stress may reduce the yield dramaticly. Screening salt-tolerant varieties can greatly improve the yield of potato crops gown in salty soil. However, it is not easy to have such varieties because of the absence of available germpalsm in Solanum tuberosum. Fouturnately, Neo-tuberosum originated from South America is a diversity resource for potato improvement, and the characteristic of salt tolerancc could be probablely found. But researches of it were rarely reported.In this paper, 1200 true potato seeds derived form 6 Neo-tuberosum recurrent selection materials were tested. Materials tolerant to salt were achieved through the preliminary screening. The tolerance to salt of selected materials was identified. In order to understand the influence of different stress periods and concentration to the plant height and biological yields, contents of proline and chlorophyll in 6 materials with various tolerances to salt were analysed. Eventually, some meterails from Neotuberosum were screened out with the reference of four varieties that grown widely, which would be helpful for improviment of germpalsm with tolerance to salt and breeding of potatoes.The results were summarized as follows:(1) In the preliminary selection of the 1200 true potato seeds, 162 seedlings were emergeed, among them 65 seedlngs were survived in MS medium plus 0.2% NaHCO3. Furthermore, tests of salt tolerance wree made to identify the tolerant extents. Among the 65 materials, 12 were classified as salt-tolerant, 24 were moderate salt-tolerant and 29 were non-salt-tolerant.(2) Under salt stress, plant height was becoming short as the increasing of salt concentration. Significant differences were found in materials, concentrations and the interaction between materials and concentrations. The correlation between plant height and salt concentriation was significant, and the smaller of the differences was bwtween salt concentrations, the stronger correlations were showed. The correlated coefficient between plant height and salt tolerance was becoming higher as the salt concentration being increased in various treatments. u(x) of materials with plant height in 5-8 cm was higher than others, which meant thoese materials were tolerant to salt in general. The possibility of screening out materials with strong tolerant to salt in those materials would be greater than in others.(3) Biological yields were gong down as the increase of salt concentration. Significant differences were found in materials, treatments and interaction between materials and concentrations. The correlation between the salt-tolerance and the biological yield were different. Under the concentration of 0.4%, the correlation was highly significant. The frequencies of salt-tolerant materials were decreased in each biological yield range as the increase of salt...