Identification of Sources of Multiple Disease Resistance in Mini-core Collection of Chickpea.

Host plant resistance is the major component in the management of fungal diseases in chickpea (Cicer arietinum). We screened a chickpea mini-core collection composed of 211 germ plasm accessions representing the diversity of the global chickpea germ plasm collection of 16,991, maintained at the International Crops Research Institute for the Semi-Arid Tropics to identify sources of multiple disease resistance. The accessions were screened for resistance against As-cochyta blight (Ascochyta rabiei), Botrytis gray mold (Botrytis cinerea), Fusarium wilt (Fusarium oxysporum f. sp. ciceris), and dry root rot (Rhizoctonia bataticola) under a controlled environment. High levels of resistance were observed to Fusarium wilt (FW), where 21 accessions were asymptomatic and 25 resistant. In all, 3, 55, and 6 accessions were moderately resistant to Ascochyta blight (AB), Botrytis gray mold (BGM), and dry root rot (DRR) respectively. ICC 11284 was the only accession moderately resistant to both AB and BGM. Combined resistance also was identified for DRR and FW in 4 accessions, and for BGM and FW in 11 accessions. Through this study, chickpea germ plasm accessions were identified that possess high levels of resistance to more than one fungal disease and would be useful in chickpea multiple disease resistance breeding programs.

Resistance of Wild Arachis Species to Late Leaf Spot and Rust in Greenhouse Trials.

Seventy-four accessions of wild Arachis species along with a susceptible line TMV 2 belonging to A. hypogaea were evaluated for resistance to late leaf spot and rust under greenhouse environment. The experiment was conducted twice to confirm the resistance of the accessions. Percentage of leaf area damaged and disease score on a 1 to 9 scale for late leaf spot and rust were recorded for all accessions in both experiments. Additionally, percentage of defoliation was recorded for late leaf spot. One accession, ICG 8190, of A. hoehnei and one accession, ICG 13199, of A. duranensis were asymptomatic to late leaf spot in both experiments. In addition, 26 accessions were classified as resistant, 10 accessions were moderately resistant, and the remaining 36 accessions exhibited a susceptible reaction to late leaf spot. Only one accession, ICG 8954 of A. kuhlmannii, remained asymptomatic to rust in both experiments. All other accessions, except ICG 8206 of A. ipaensis, ICG 8197, ICG 8198, ICG 11549, and ICG 13178 of A. monticola, and ICG 13171 of A. stenosperma were classified as highly resistant to rust. Four accessions of A. monticola were susceptible to late leaf spot and rust.