Resistance to groundnut rosette disease in wild Arachis species

Abstract

SummaryOne hundred and sixteen accessions representing 28 species in the genus Arachis were evaluated for resistance to groundnut rosette disease using an infector row technique during the 1996/97, 1997/98, 1998/99 and 1999/2000 growing seasons at Chitedze, Malawi. Of these, a total of 25 accessions belonging to Arachis diogoi (1 accession), A. hoehnei (2), A. kretschmeri (2), A. cardenasii (2), A. villosa (1), A. pintoi (5), A. kuhlmannii (2), A. appressipila (3), A. stenosperma (5), A. decora (1), and A. triseminata (1) showed resistance to the groundnut rosette disease. No visible disease symptoms were observed in several accessions belonging to A. appressipila, A. cardenasii, A. hoehnei, A. kretschmeri, A. villosa, A. pintoi, A. kuhlmannii, and A. stenosperma. Some accessions in A. appressipila, A. diogoi, A. stenosperma, A. decora, A. triseminata, A. kretschmeri, A. kuhlmannii, and A. pintoi were resistant to all three components of rosette, Groundnut rosette ass is tor virus (GRAV), Groundnut rosette virus (GRV) and its satellite RNA (sat. RNA). Two accessions in A. stenosperma and one accession in A. kuhlmannii showed the presence of all three components of the rosette disease. Several wild Arachis accessions were resistant to GRAV. All the accessions of A. batizocoi (4), A. benensis (2), A. duranensis (46), A. dardani (1), A. ipaensis (1), A. magna (1), A. monticola (3), A. oteroi (1), A. pusilla (4), and A. valida (2) were susceptible to rosette disease. In all these accessions, infected plants were chlorotic and severely stunted. The value of exploitation of the resistance in wild Arachis species in rosette resistance breeding programmes is discussed.