Kusum Mathur

Identification of quantitative trait loci associated with resistance to foliar diseases in sorghum [Sorghum bicolor (L.) Moench]

Forage sorghum cultivars grown in India are susceptible to various foliar diseases, of which anthracnose, rust, zonate leaf spot, drechslera leaf blight and target leaf spot cause severe damage. We report here the quantitative trait loci (QTLs) conferring resistance to these foliar diseases. QTL analysis was undertaken using 168 F7 recombinant inbred lines (RILs) of a cross between a female parental line 296B (resistant) and a germplasm accession IS18551 (susceptible). RILs and parents were evaluated in replicated field trials in two environments. A total of twelve QTLs for five foliar diseases on three sorghum linkage groups (SBI-03, SBI-04 and SBI-06) were detected, accounting for 6.9–44.9% phenotypic variance. The morphological marker Plant color (Plcor) was associated with most of the QTL across years and locations. The QTL information generated in this study will aid in the transfer of foliar disease resistance into elite susceptible sorghum breeding lines through marker-assisted selection.

Efficacy of different fungicides and bio-agents against wilt and root rot complex of chickpea

The present investigation were undertaken to develop an effective strategy for the integrated management of wilt and root rot complex diseases of chickpea (Cicer arietinum L.), which is widely prevalent in moderate to high severity in different parts of Rajasthan. The pathogens were isolated from disease chickpea plants showing typical wilt and root rot symptoms collected from farmers field of different chickpea growing areas of Rajasthan. Fusarium oxysporum f. sp. ciceri (one isolate), Fusarium solani (five isolates) and Rhizoctonia solani (six isolates) were isolated and their pathogenicity was confirmed by growing chickpea in pathogen inoculated soil. The fungicides, botanicals and biocontrol agents found effective in vitro, were further evaluated in field for two consecutive seasons as seed treatment individually as well as in combinations for suppression of wilt and root-rot complex of chickpea. It was found that combined treatments were superior in terms of better germination, lower mortality and higher yield as compared to the individual treatments. The most effective treatment was seed treatment with tebuconazole + T. harzianum followed by vitavax+T. harzianum as compared to control as well as other treatments.