Evaluation of Gossypium species for resistance to cotton leaf curl Burewala virus

Abstract

Cotton leaf curl disease (CLCuD), caused by cotton leaf curl Burewala virus (CLCuBV), has emerged as a major threat to cotton production in Pakistan. Resistance to CLCuBV was evaluated in cultivated and wild cotton genotypes representing six Gossypium species by visual symptom scoring and virus assessment using PCR tests. Considerable variation in responses was observed when using whitefly and graft transmission to inoculate Gossypium genotypes with CLCuBV in field and greenhouse experiments. Under field evaluation, all cultivated genotypes of Gossypium hirsutum and three genotypes of G. barbadense were susceptible. Eleven genotypes that represented six wild and cultivated Gossypium species were considered to be highly resistant as they were free from infection. Similar results were obtained when these genotypes were tested using whitefly transmission. To verify these findings, 132 cultivated and wild genotypes were tested by graft inoculation. All G. hirsutum genotypes (116 cultivated, 1 wild, 1 transgenic Coker‐312 and 1 non‐transgenic Coker‐312), three G. barbadense genotypes and one G. thurberi genotype were highly susceptible and exhibited symptoms 9–12 days after grafting. Four genotypes of G. arboreum and one genotype of G. anomalum did not express symptoms but had a detectable level of virus. One genotype of G. herbaceum and three wild genotypes of G. hirsutum showed mild symptoms (severity indexes of 1–2) and exhibited delayed disease development. These genotypes were classified as moderately resistant to resistant. Resistant genotypes that were identified in this study will be useful sources for exploitation of breeding programmes aimed at developing CLCuBV‐resistant varieties and increasing genetic diversity.

NIAB-2008: A New High Yielding and Long Staple Cotton Mutant Developed through Pollen Irradiation Technique

“…For grafting studies, ten pots each for each variety were sown in glass house. Graft inoculation of the plants with CLCuV-B was done by following the bottle shoot grafting method (Akhtar et al, 2002(Akhtar et al, , 2010. Results showed that number of days taken to appear the symptoms (after grafting) in case of NIAB-2008 were 14-20 compared to 12-18 of MNH-786 (Table 7).…”

“…For grafting studies, ten pots for each variety were sown in glass house. Plants were graft inoculated with CLCuV-B following the methodology of bottle shoot grafting method ( Akhtar et al, 2002Akhtar et al, , 2010. Entomological studies regarding its response to sucking pests and damage by bollworms were conducted under optimized spray conditions at NIAB Faisalabad.…”

Assessing genetic diversity among six populations of Gossypium arboreum L. using microsatellites markers

“…arboreum (also known as Asiatic cotton) germplasm collection is an important genetic resource for tetraploid cotton improvement. G. arboreum has certain inherent qualities, which the tetraploids lack, like the ability to withstand drought and salinity (Maqbool et al 2010;Tahir et al 2011) and remarkable tolerance to several pests and disease, including bollworms (Dhawan et al 1991), aphids and leafhoppers (Nibouche et al 2008), rust, fungal (Wheeler et al 1999) and viral (Mehetre et al 2004;Akhtar et al 2010) diseases. Natural G. arboreum fibers display various colours (e.g.…”

Linkage disequilibrium and association mapping of fibre quality traits in elite Asiatic cotton (Gossypium arboreum) germplasm populations

“…It has inherent resistance to various biotic (Akhtar et al 2010) and abiotic stresses (Tahir et al 2011); tetraploids lack these qualities (Kulkarni 2002). Natural G. arboreum fibres display various colours (e.g.…”