RESUMO
Background: Gossypium arboreumis resistant to Cotton leaf curl Burewala virus and its cognate Cotton leaf curl Multan beta satellite [CLCuBuV and CLCuMB]. However, the G. arboreum wax deficient mutant [GaWM3] is susceptible to CLCuV. Therefore, epicuticular wax was characterized both quantitatively and qualitatively for its role as physical barrier against whitefly mediated viral transmission and co-related with the titer of each viral component [DNA-A, alphasatellite and betasatellite] in plants
Objectives: The hypothesis was the CLCuV titer in cotton is dependent on the amount of wax laid down on plant surface and the wax composition
Materials and Methods: The wax was isolated by decoction method and analysed by GC-MS whereas viral particles were quantified by Real-Time PCR. The whitefly feeding assay was performed on plant in Hoagland solution with 1% Nile Blue Dye and color was observed in the gut of whiteflies
Results: Analysis of the presence of viral genes, namely alphasatellite, betasatellite and DNA-A, via real-time PCR in cotton species indicated that these genes are detectable in G. hirsutum, G. harknessii and GaWM3, whereas no particle was detected in G. arboreum. Quantitative wax analysis revealed that G. arboreum contained 183 micro g.cm[-2] as compared to GaWM3 with only 95 micro g.cm[-2]. G. hirsutum and G. harknessii had 130 micro g.cm[-2] and 146 micro g.cm[-2], respectively. The GCMS results depicted that Lanceol, cis was 45% in G. harknessii. Heptadecanoic acid was dominant in G. arboreum with 25.6%. GaWM3 had 18% 1,2,-Benenedicarboxylic acid. G. hirsutum contained 25% diisooctyl ester. The whitefly feeding assay with Nile Blue dye showed no color in whiteflies gut fed on G. arboreum. In contrast, color was observed in the rest of whiteflies
Conclusions: From results, it was concluded that reduced quantity as well as absence of [1] 3-trifluoroacetoxytetradecane, [2] 2-piperidinone,n- 4-bromo-n-butyl, [3] 4-heptafluorobutyroxypentadecane, [4] Silane, trichlorodocosyl-, [5] 6-Octadecenoic acid, methyl ester, and [6] Heptadecanoicacid,16-methyl-,methyl ester in wax could make plants susceptible to CLCuV, infested by whiteflies
RESUMO
Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.