Phenotypic diversity and identification of wild Arachis accessions with useful agronomic and nutritional traits

Abstract

Wild relatives harbor novel sources of variation, which can be used to enhance the genetic base of a cultivar gene pool. A total of 269 accessions from 20 wild Arachis species belonging to six sections were evaluated for 41 morpho-agronomic traits and 89 selected accessions for oil, protein and total sugar content. Six plants from each accession were grown in an open Arachis house in largecylindrical concrete structures during the 2004-2005 season at Patancheru, India. REML analysis showed significant differences between species and accessions for most of the traits studied. Hierarchical cluster analysis, based on the first five principal component scores accounted for 82.5% variation, resulting in four clusters. Variation in genome relationships and ploidy levels had no bearing on the clustering pattern which was predominated by life forms: clusters 1 and 2, contained mostly annuals and clusters 3 and 4 perennials. A large range of variations were noticed among species for some of the agronomic traits: days to flowering, pod and seed characteristics, specific leaf area (SLA) and for SPAD chlorophyll meter reading (SCMR). Arachis duranensis showed the maximum intraspecific variation as revealed by a high diversity index for 23 of the 41 traits which included: days to flowering, primary branches, plant width, pod length, pod width, SCMR and SLA. The other species with desirable traits were A. pusilla (earliest flowering) and A. villosa (high SCMR at 60 and 80 days after sowing). The latter species is cross compatible with cultivated groundnut, thus, is a good source to enhance the trait value in the cultigen's gene pool. The best 20 accessions with superior agronomic, nutritional quality and drought related trait combinations have been identified for their use in introgression of diverse and unique alleles from wild Arachis species into A. hypogaea.

Utilizing Wild Species for Peanut Improvement

“…As compared with accessions in the A. hypogaea collection, extremely high levels of resistance have been identified in Arachis species for many important peanut pathogens and insects (Stalker and Moss, 1987;Dwivedi et al, 2007) ( Tables 3 and 4). In addition, Upadhyaya et al (2011) identified superior accessions of wild peanuts for both agronomic and nutritional quality traits, including days to flowering and high levels of percentage of oil, protein, and sugars. Important for crop improvement are the 29 diploid (2n = 2x = 20) species in section Arachis, because these materials will hybridize with the cultivated peanut.…”

Groundnut improvement: use of genetic and genomic tools

“…Genetic variability for yield and yield attributes, resistance/tolerance to foliar fungal diseases (Singh et al, 2003), insect pests (Lynch, 1990), root-knot nematode (Simpson et al, 1993), traits for confectionary uses (Dwivedi and Nigam, 2005), oil content and quality (Upadhyaya et al, 2011), haulm yield and quality traits (Nigam and Blummel, 2010), and several other traits of economic importance were reported in literature (see Table 1 ). The germplasm accessions of cultivated groundnut in the gene banks are a vast repository of this variation.…”

Genetics, Genomics and Breeding of Peanut: An Introduction

“…The other species with desirable traits was A. villosa (high SCMR at 60 and 80 days after sowing). The best 20 wild Arachis accessions, possessing one to fi ve desirable agronomic, nutritional and drought related traits identifi ed in this study were ICG 8144 (A. villosa) high in SCMR, low SLA, high sugar content; ICG 3223, 13244, 14868, 14872, 14874, 14884 (A. stenosperma) superior in pod length and width and/or seed length and width; ICG 13211 (A. pusilla) earliest to fl ower; ICG 13178 (A. monticola) and ICG 13189 (A. duranensis) high in sugar; ICG 15142 (A. pusilla) and ICG 13227 (A. dardani) high in protein ), which may be exploited to broaden the genetic base of cultivated peanut (Upadhyaya et al 2011b).…”