Verticillium wilt is one of the main diseases in cotton (Gossypium hirsutum), severely reduces yield and fiber quality, and is difficult to be controlled effectively. At present, the molecular mechanism that confers resistance to this disease is unclear. Transcriptome sequencing is an important method to detect resistance genes, explore metabolic pathways, and study resistance mechanisms. In this study, the transcriptome of a disease-resistant inbred cotton line inoculated with Verticillium dahliae was sequenced.
Understanding how microbial community composition and diversity respond to continuous cropping obstacle is not well understood. However, determining the community composition vs assessing the diversity of molecular operational taxonomic units is often difficult. In this study, we focused on the microbial diversity and niche differentiation in rhizosphere soils between healthy and diseased cotton using a molecular approach based on a culture-independent method.
Plant molecular identity (ID) is used to describe molecular characteristics of plants, which should contain all of the necessary information. Using inter-simple sequence repeat (ISSR) primers, molecular ID can be described in a way that reflects the polymerase chain reaction (PCR) conditions, annealing temperature, and the bands obtained in PCR amplification. A new complete molecular ID system is described in this study, which can be easily used and expanded to include more information.
We screened and assessed published cotton simple sequence repeat (SSR) primers to establish a set of core SSR markers suitable for cotton major cultivars in China and analyzed genetic diversity based on the core marker set. Using a stepwise screening strategy, 12 leading cultivars for preliminary screening and 96 cultivars for rescreening were evaluated. A total of 184 polymorphic SSR markers were initially screened from 3299 candidates, and a core set of 52 SSR markers with wide genome coverage (2 markers per chromosome) was obtained.
Cotton is an important cash crop worldwide, accounting for a large percentage of world agricultural exports; however, yield per acre is still poor in many countries, including Pakistan. Diallel mating system was used to identify parents for improving within-boll yield and fiber quality parameters. Combining ability analysis was employed to obtain suitable parents for this purpose. The parental genotypes CP-15/2, NIAB Krishma, CIM-482, MS-39, and S-12 were crossed in complete diallel mating under green house conditions during 2009.
Twenty-one isolates of Rhizoctonia solani were categorized into three anastomosis groups consisting of AG-4-HG-I (eight isolates), AG-2-2 (nine isolates) and AG-5 (four isolates). Their pathogenic capacities were tested on cotton cultivar Giza 86. Pre-emergence damping-off varied in response to the different isolates; however, the differences were not significant. Soluble proteins of the fungal isolates were electrophoresed using SDS-PAGE and gel electrophoreses.
Research pertaining to genetic variability parameters, heritability, and genotypic, phenotypic, simple, and environmental correlations for various seedling traits in five elite advanced cotton (Gossypium hirsutum L.) lines (FH-113, FH-114, FH-941, FH-942, and FH-2015) and one check (CIM-496) was carried out during October and November 2010 under greenhouse conditions at the Cotton Research Institute (Faisalabad, Pakistan). Material was raised in plastic tubes with a randomized complete block design replicated three times.
The genetic distance of 11 cotton genotypes varying in heat tolerance was studied using RAPD markers. Fifty-three random decamer primers were used for the estimation of genetic distance. Among the 53 RAPD primers, which were custom synthesized by GeneLink Inc., UK, 32 were polymorphic and 21 were monomorphic. The 32 polymorphic primers produced 273 fragments, with a mean of 8.3 fragments per primer. The number of polymorphic bands produced in the 11 cotton accessions ranged from 1 to 31.