Efficient use of crop germplasm resources: identifying useful germplasm for crop improvement through core and mini-core collections and molecular marker approaches

Abstract

Conservation of crop germplasm diversity involves the establishment of in situ and ex situ genebanks. The major activities for ex situ genebanks include assembling, conserving, characterizing and providing easy access to germplasm for scientists. More than six million accessions are currently assembled in over 1300 genebanks worldwide. ICRISAT is one of the 15 CGIAR centres, with headquarters at Patancheru, India, and conserves genetic resources of sorghum, pearl millet, chickpea, pigeonpea, groundnut, and six small millets. The ICRISAT genebank holds 114,870 accessions from 130 countries, including both archival materials from various organizations throughout the world, and from fresh collections resulting from 213 missions in 62 countries. The ICRISAT genebank supplies annually over 40,000 germplasm samples to scientists worldwide. Sixty-six varieties selected from the basic germplasm have been released for cultivation in 44 countries, and ICRISAT has restored/repatriated crop germplasm to eight countries. The research focus is on germplasm diversity assessment, developing core and mini-core collections, and using a molecular characterization approach to both enhance the utilization of germplasm in research and improve the efficiency of germplasm management. Following these approaches, we have been able to identify a significant number of accessions with traits potentially relevant for crop improvement.

Microsatellite marker-mediated analysis of the EMBRAPA Rice Core Collection genetic diversity

“…Worldwide, more than six million accessions of different species are currently assembled in over 1,300 different genebanks (Upadhyaya et al 2006), and rice germplasm collections count as one of the largest ex situ genebanks (Ni et al 2002). It is estimated that more than 400,000 rice germplasm accessions are conserved in genebanks around the world, and the majority (*75%) of accessions are stored in six genebanks located in Asian countries, such as China, Japan, India, Thailand, Korea and Philippines (Hamilton and Raymond 2005).…”

Transcriptome Sequencing of Diverse Peanut (Arachis) Wild Species and the Cultivated Species Reveals a Wealth of Untapped Genetic Variability

“…Evaluation has demonstrated significant phenotypic diversity for numerous traits, including resistance to leaf spots, tomato spotted wilt virus, other biotic stresses, for tolerance to drought or heat stress, and for early maturity (Isleib et al 1995; Anderson et al 1996; Upadhyaya 2003, 2005, Upadhyaya et al 2006a,b; Selvaraj et al 2011; Wang et al 2011a; Jiang et al 2014; Pandey et al 2014; Singh et al 2014). To date, these have not been accompanied by molecular characterization at SNP levels.…”

Pearl millet

“…The use of available genetic resources in crop improvement is the most neglected part of germplasm conservation (de Wet, 1989). A very large gap exists between actual utilization of the germplasm and availability of collection in the genebanks (Wright, 1997;Upadhyaya et al, 2006). Germplasm resources would not be used if the information needed by crop improvement scientists is not readily available.…”