Genome-wide association mapping of stress-tolerance traits in cotton

Environmental stresses severely impair cotton production worldwide. To identify the genetic basis of, and molecular markers associated with, environmental stresses such as salt, cold and Verticillium wilt, association mapping of salt-, cold-, and disease-tolerance traits was performed in a population of 503 upland cotton accessions using 179 polymorphic SSR markers and 11,975 array-derived SNP markers. Salt and cold tolerance was evaluated via the relative germination rate(RGR) of the seeds under seven and four environments, respectively. The disease index of Verticillium wilt was investigated for two years in the field in Xinjiang. These three traits showed large variation across environments. A genome-wide association study revealed that 31, 19, and 15 SSR markers were associated with RGR-Salt(the relative germination rates of seeds under salt stress),RGR-Cold(the relative germination rates of seeds under cold stress), and DIV(the disease index of Verticillium wilt), respectively. Six SNPs in seven environments and two SNPs in BLUP(best linear unbiased prediction) results were associated with RGR-Salt, and the phenotypic variance explained ranged from 3.96 to 5.00%. Two SNPs(i02237 Gh, i02243 Gh)on D01 were concluded to be stable genetic loci associated with RGR-Salt. A total of 223 genes were found in a candidate gene interval(D01, 37771–1942912). Of these four genes,GhPIP3A, GhSAG29, GhTZF4, and GhTZF4a, showed expression changes in sensitive and tolerant genotype accessions under salt stress, and were assigned as candidate genes associated with RGR-Salt. This study revealed the genetic basis of stress resistance in upland cotton and will facilitate stress-resistance breeding in cotton.

Advances and prospects of genetic mapping of Verticillium wilt resistance in cotton

Verticillium wilt is one of the most important diseases affecting cotton production in China.The fungus,Verticillium dahliae,has a wide host range and a high degree of genetic variability.No resistance resources have been found in the available planting resources,thus presenting difficulties and challenges for our study.The long-term production practice shows that selection of disease-resistant varieties is the most economical and effective measure to control Verticillium wilt of cotton to reduce the yield loss and quality decline of cotton.In this paper,we summarized the genetic mapping population,the analysis method of genetic localization,the discovery,mining and cloning of disease-resistant quantitative trait loci/markers,and the analysis of their genetic functions,so as to provide information for the molecular breeding approach of disease-resistant cotton.

Remote real-time monitoring soil water potential system based on GSM

Aiming at the limitation of traditional measuring soil water potential, the paper presents an information system based GSM to real-time monitor data coming from multiple data sources. The monitoring system, which consisted of monitoring center, GSM transmission channel and data detection terminal, was given. The detection terminal included the measuring station and TS-2 negative pressure meter, which was applied to measure soil water potential. Nowadays the system has been successfully applied to drip irrigation in the cotton field on farm in Xinjiang region. The system provides a feasible technology frame-work for collecting and processing wide geographical distribution data in farmland.

Studies on cDNA Probe Detection Technology for Apple Stem Pitting Virus in Kuala Pear

Using Kuala pear leaves and cortexes as materials, the total RNA was extracted using two methods and these two methods were compared. The most suited methods for Kuala pear were screened; and biotin-labeled cDNA probe was synthesized using RT-PCR. The main factors that affected the sensitivity of hybridization were studied. Studies indicated that the highest sensitivity was obtained under the following conditions： probe concentration 400 ng mL^-1, formamide concentration 45%, temperature 42℃, hybridization time 6 hours. The best hybridization results were obtained when the nitrocellulose membrane purchased from Gelman was used. Better blocking of hybridization was obtained using Tween 20 compared with albumin in bovine. The detection of the total RNA using different tissues and different extraction methods was compared. This study indicates that the total RNA of fresh leaf, old leaf, cortexes, and frozen leaf showed signs of hybridization using the two extraction methods.