Mungbean (Vigna radiata (L.) Wilczek), also known as greengram, is the most widely cultivated Asian Vigna species. Improved mungbean cultivars have a narrow genetic base that limits yield potential and they are poorly adapted to varying growth conditions in different agro-ecological conditions. The genetic potential of landrace germplasm accessions in gene- banks therefore needs to be better exploited. Germplasm core collections are made of a reduced set of representative accessions from the entire diversity maintained by genebanks. This subset of accessions can be used for testing general combining ability with local germplasm in the search for yield enhancement. Core collections also help breeders in selecting parental material that could maximize potential genetic gain from derived hybrid populations. At the National Bureau of Plant Genetic Resources (NBPGR), India, genetic enhancement/pre- breeding studies in mungbean have been initiated involving diverse parents mainly from the cultivated gene pool, using the Bureau's core collection as starting material. Germplasm enhancement aims at widening the genetic base of breeding materials by transferring desired genes from unimproved germplasm into enhanced varieties. Mild and decentralized selected material was maintained in target sites across the country. A total of 102 progenies were advanced to F5 for further selection and use by the breeders in Delhi. The genetic potential of a few selected enhanced progenies with desired plant types and better yield-related traits is presented in this paper. The study clearly demonstrates the potential of germplasm accessions conserved in genebanks for use in large-scale base-broadening efforts in mungbean.

Diversity in agronomically important traits of wild emmer wheat, Triticum dicoccoides, the progenitor of most cultivated wheats, was examined in l60 genotypes representing 16 populations derived from a wide ecogeographical spectrum of climate, soil and water availability in Israel and Turkey. The analysis included 14 quantitative economic characters including heading date, culm length, biomass, grain yield and its components, and grain protein percentage.

The results led to two major conclusions: (i) agronomically important traits varied genetically: ecogeographic diversity in these traits is dramatically displayed when populations are grown in a relatively standardized environment; and (ii) genetic diversity is revealed not only between, but also within populations. Thus, genotypes excelling in some of these characters were found in several populations.

Southern Sudan has a low population density, abundant land and tremendous agricultural potential. A large number of domesticated crops are grown in the region in a range of cropping systems. There are also numerous useful wild plant genetic resources. Little collecting work has been done in the region, there are few accessions from southern Sudan stored ex situ and publications on the actual and potential plant genetic resources for agriculture are sparse. The region has been a centre of civil conflict with little respite since independence in 1956. The farmers’ fields and natural environments represent in situ genebanks, which following the cessation of hostilities will become extremely important for the rehabilitation of subsistence agriculture, the promotion of cash crop production and the revitalization of the regional economy. Several wild plant species are highly nutritious and merit the attention of plant scientists. This article describes some of the domesticated, semi-domesticated and wild plant genetic resources of the area, and suggests why these are important for agricultural rehabilitation following implementation of a peace accord.

Wild relatives of crop species are known to be sources of genetic diversity that can be used in crop improvement. However, they have not always been studied adequately for the variation that may exist within them, for traits which may have important implications from an evolutionary point of view and their use in breeding programmes. In the present study, a wild groundnut species, Arachis stenosperma, has been studied for variation between accessions collected from different sites in Brazil for morphological and certain nutritional traits, and for disease resistance. Multivariate analysis of 23 characters grouped 18 accessions into two clusters, while one accession, ICG 14927, was distinct from these. However, in protein profile they all appear identical. Hence, the variation appears to have arisen in response to the climatic conditions of their habitat, which has implications for use of these accessions in breeding programmes. The variation in these traits could not be associated with any phytogeographical regions. The dispersal of this species from its centre of origin and diversity to other parts of Brazil appears to be recent and without any identifiable selection pressures having operated.

A set of 68 simple sequence repeat (SSR) markers were selected from existing databases (including Medicago, soybean, cowpea and peanut) for the purpose of exploiting the transferability of SSRs across species and/or genera within the legume family. Primers were tested for cross-species and cross-genus fragment amplification with an array of 24 different legume accessions. Nearly one-third (30.78%) of the SSR primers screened generated reproducible and cross-genus amplicons. One hundred and seventeen cross-species polymorphic amplicons were identified and could be used as DNA markers. These polymorphic markers are now being used for characterization and evaluation of our collected and donated legume germ- plasm. The transferability of SSRs, mis-/multiple-primings, homologous/heterologous amplifications, single/multiple-amplicons and application of these amplicons as DNA markers are discussed. The transfer of SSR markers across species or across genera can be a very efficient approach for DNA marker development, especially for minor crops.

DNA profiles of 92 banana and plantain cultivars were generated with 12 amplified fragment length polymorphism (AFLP) primer pairs. The average polymorphism information content (PIC) values of the polymorphic AFLP markers varied from 0.270 to 0.341, and the profiles could distinguish all the 92 cultivars analysed. It was possible to identify differences between two accessions of the AAB genome cultivar Rasthali, indicating the presence of intra-cultivar genetic variation. A UPGMA (unweighted pair group method of arithmetical means) dendrogram generated with 1581 AFLP products identified four major clusters, each comprising cultivars of similar genomic constitution. All the ABB cultivars grouped in a single cluster, which was well separated from the rest. The within-group similarity coefficients indicated that the most diverse group was AAB, followed by AAA. However, significant genetic diversity was also present among AA, AB and ABB Indian banana cultivars, supporting the notion that India, along with other neighbouring south-eastern Asian countries, is the centre of diversity for cultivars of banana and plantain. The presence of substantial diversity among the banana and plantain landrace cultivars could be exploited in varietal improvement programmes.

Identification of sugarcane hybrids is difficult when selections are based solely on morphological traits. Our objective was to combine morphological traits and molecular marker analysis to select F1 hybrids from two separate crosses between Djatiroto, a clone of Saccharum spontaneum, and elite sugarcane clones, LCP 85-384 (Cross 97-3144) and CP 62-258 (Cross 97-3146). The maternal inflorescences of Djatiroto were emasculated by submersion in a circulating 45°C hot-water tank for 10 min to minimize self-fertilization. Cross 97-3144 produced 4.7 g of seeds with 338 viable seeds per gram and Cross 97-3146 produced 2.4 g of seeds with 166 viable seeds per gram. After greenhouse germination, 96 progeny from each cross were evaluated in a field plot. Evaluations were conducted on the ratoon crops for stalk diameter (mm), juice Brix (percentage soluble solids), and a randomly amplified polymorphic DNA (RAPD) marker OPA-11-366 that was reproducibly amplified through PCR from the elite clones, but not the maternal S. spontaneum clone. Fifty progeny (52.1%) from Cross 97-3144 and 36 progeny (37.5%) from Cross 97-3146 inherited the RAPD marker. Five putative F1 progeny were selected from each cross, namely US 99-43, US 99-44, US 99-45, US 99-46 and US 99-47 from Cross 97-3144, and US 99-48, US 99-49, US 99-50, US 99-51 and US 99-52 from Cross 97-3146, based on their relatively larger stalk diameter, higher Brix and inheritance of the RAPD marker. The hybrid nature of these selected progeny was verified with sugarcane microsatellite markers. This is the first report of the development of Saccharum hybrids with the cytoplasm of S. spontaneum for breeding purpose through a combination of conventional and molecular breeding approaches. Availability of these F1 hybrids could enhance the genetic diversity of Saccharum germplasm and has enabled sugarcane geneticists and breeders to explore the possible contribution of S. spontaneum cytoplasm in the development of new sugarcane cultivars.