Study On Abiotic Stress Resistance And Related Genes In Seed Peanuts

Peanut（Arachis hypogaea L.） is an important cash crop in China, and its annual planting area, total production and export took lead in the world. Usually planted in dry and low-fertility soils, the peanut crop is frequently affected by drought, low temperature, nutrients deficiency,diseases and insect pests, resulting in reduced yield and inferior quality. Good quality, stress resistance and high yields are the major breeding of peanut. High vigor seeds play an important role to ensure the peanut production because high vigor seeds have not only mean an high emergence percentage, robust seedlings and good stress resistance. This thesis studied 3 quality aspects of seed peanuts.1. Two high oleic acid peanut cultivars, Huayu 661 and Huayu 662 were chosen to study their storability in in-house test and field experiments. New and old seed peanuts were respectively harvested in autumn, 2013 and 2014. In-house test and near infrared scan were conducted to find if natural aging had some influence on seed quality parameters of high oleic acid peanuts, as well as seed quality and nutritional quality in the next generation. Sown in spring and harvested in September 2015, peanuts were cultivated under film mulch to find out if natural aging affects emergence rate of pod and seed.Results showed that for seed germination potential, significant difference was only detected in Huayu 662, and for leaching liquid conductivity, significant difference was only detected in Huayu 661. For each high oleic acid peanut cultivar, field emergence and pod and seed yields between old and new seeds were not significantly different.There was no significant difference between seeds harvested from new and old high oleic acid seed peanuts in germination potential, germination rate, germination index, vigor index and simplified vigor index. There was no significant difference in nutritional quality parameters of oleic acid, fat and sucrose content. But some difference was recorded in palmitic acid and protein content. This research results may help to regulate peanut seed supply in scanty and surplus years, but provide some clues to solve the problem in south China, where spring peanut failed to be used as seeds for next year’s planting, simply because of severely reduced seed vigor.2.An MYB over-expression vector was constructed, and was transformed into peanut using Agrobacterium-mediated gene transfer system. DNA was extracted from the resultant seeds and T1 seeds were identified by PCR screening. A transgenic peanut seeds was used in low temperature treatment（2℃48h） and subsequent normal temperature germination test（25℃72h）.Results showed that as compared with non-transgenic peanut, the peanuts with over-expression vector of MYB gene showed high low temperature resistance.3.The calcium dependent protein kinase（CDPK） gene named Ah CDPK32 was firstly cloned from the cultivated peanut "shanyou 21" mature seeds by RT-PCR method, whose sequence contained 1617 bp and encodes 538 amino acids. Nucleotide sequence homology in the NCBI blast compared with soybean Gm CDPK32（XM₀03554131） was 87%. Its molecular weight was predicated to be 60.807 k D and p I 6.96. The analysis of protein hydrophobicity and signal peptide showed that there was a small possibility of the signal peptide sharing, and the protein was hydrophilc. A gene over-expression vector p Cambia-Ah CDPK32 was built, paving the way for further research of the gene function.