Molecular markers for late blight resistance breeding of potato: an update

Late blight is the most devastating disease of the potato crop that can be effectively managed by growing resistant cultivars. Introgression of resistance (R) genes/quantitative trait loci (QTLs) from the Solanum germplasm into common potato is one of the plausible approaches to breed resistant cultivars. Although the conventional method of breeding will continue to play a primary role in potato improvement, molecular marker technology is becoming one of its integral components. To achieve rapid success, from the past to recent years, several R genes/QTLs that originated from wild/cultivated Solanum species were mapped on the potato genome and a few genes were cloned using molecular approaches. As a result, molecular markers closely linked to resistance genes or QTLs offer a quicker potato breeding option through marker‐assisted selection (MAS). However, limited progress has been achieved so far through MAS in potato breeding. In near future, new resistance genes/QTLs are expected to be discovered from wild Solanum gene pools and linked molecular markers would be available for MAS. This article presents an update on the development of molecular markers linked to late blight resistance genes or QTLs by utilization of Solanum species for MAS in potato.     

Potato apical leaf curl disease: current status and perspectives on a disease caused by tomato leaf curl New Delhi virus

Journal of Plant Diseases and Protection - Potato apical leaf curl disease (PALCD) caused by a unique bipartite virus [tomato leaf curl New Delhi virus (ToLCNDV)] has emerged as a global threat....     

Enhanced protection against two major fungal pathogens of groundnut, <Emphasis Type="Italic">Cercospora arachidicola</Emphasis> and <Emphasis Type="Italic">Aspergillus flavus</Emphasis> in transgenic groundnut over-expressing a tobacco β 1–3 glucanase

Groundnut is an important oilseed crop of the Indian subcontinent. Yield losses due to fungal diseases are enormous in the cultivation of this crop. Over-expression of PR proteins leads to increased resistance to pathogenic fungi in several crops. The PR protein glucanase hydrolyses a major cell-wall component, glucan, of pathogenic fungi and acts as a plant defense barrier. We report in this paper, overexpression of a tobacco glucanase in transgenic groundnut and its resistance towards Cercospora arachidicola and Aspergillus flavus. PCR, Southern and Northern hybridization confirmed stable integration and expression of the glucanase gene in groundnut transgenics. When screened for resistance against Cercospora arachidicola the transgenics showed not only reduction in the number of spots but also delay in the onset of disease. Resistance was also demonstrated against one another important pathogen of groundnut, Aspergillus flavus. The transgenics not only resisted hyphal spread but also did not accumulate aflatoxin in the seeds. The results demonstrate the potential of a PR protein from a heterologous source in developing fungal disease resistant groundnut.