Grasspea (Lathyrus sativus L.) is an annual, herbaceous, drought-resistant legume and staple crop in Asian and African countries. Little is known about the nature and the amount of genetic diversity present in existing grasspea seed collections, yet this information is pivotal for future breeding programmes, such as those striving to reduce high neurotoxin levels present in seeds. Here we report on the level of genetic diversity within a world-wide collection of L. sativus, determined by isozymatic analysis. Although grasspea is generally considered a predominantly self-pollinating species, we found that the population genetic structure of these accessions showed a considerable outcrossing rate of 36%. The identification of a mixed mating system in L. sativus has significant implications for collecting and multiplying genetic resources for conservation and for future breeding purposes. In addition, we determined the genetic closeness of grasspea accessions from different geographical regions around the world. While we noticed an allelic richness in this species that was conserved across the regions, we did not find any evidence of high genetic identity between accessions, even when originating from the same geographical location. Instead, we found that greater genetic variability existed at the intra-regional level than at the inter-regional level.

Kamut wheat, said to have been derived from seed found in the Egyptian pyramids, appeared on the market about 25 years ago. We have investigated its taxonomic placement using microsatellite genotyping. In all, 89 accessions of 13 tetraploid wheat species, along with samples of Kamut wheat, were genotyped using two A and B genome wheat microsatellite markers per chromosome, generating 453 alleles (8–33 alleles per locus), and a mean allelic polymorphic information content (PIC) of 0.80. A diversity analysis showed that nine major accession groups could be defined, and these were inconsistent with formal taxonomic classifications of about 10% of the material. Most of these misclassifications are due to either species introgression or seed admixture. Some accessions appear to be duplicates. The Kamut wheats grouped together in a cluster containing three accessions of Triticum polonicum and three of T. durum, originating from Turkey, Iraq, Iran and Israel. We suggest that Kamut perhaps derived from a natural hybrid between T. durum and T. polonicum, which occurred in the Fertile Crescent.

Amplified fragment length polymorphism (AFLP) markers were employed to assess intraspecific variability in water yam (Dioscorea alata L.). Fifty-three accessions of diverse geographic origins in West and Central Africa (Benin, Côte d'Ivoire, Ghana, Nigeria and Chad) and Puerto Rico were analysed using three AFLP primer combinations. Of the 342 amplification products generated, a mean of 53.4% were polymorphic. Genetic similarity coefficients ranged from 0.29 to 0.95. The accessions could be clustered into three major genetic groups with one outlier. Each group was a mixture of accessions of different geographical origin indicating that geography has not played a major role in the differentiation of the species. A few accessions clustered very tightly suggesting that there may be duplicate accessions in the collection. The wide genetic variation observed constitutes a good basis for genetic improvement of yam.

Southern Sudan has a rich tree flora. Trees are important in the livelihoods of the numerous tribes of the region, who use them for shelter, fuel, food, fodder, medicine and income generation. The gallery and depression forests contain valuable timber trees. Other species provide non-timber forest products that are potentially tradable outside Sudan, particularly in African countries that have over-exploited their own forest resources. As the carrying capacity of the western and central areas of Sudan decreases, the pressure on the natural resources of the higher rainfall southern areas will increase. This in itself might initiate conflict, as various tribes compete over a relatively rich resource base. The recent peace established between the north and south could result in depletion of the forest resources of the south through commercial exploitation. This paper details and discusses the wild tree resources of southern Sudan, including many already threatened species.

A chickpea collection of 1600 desi and 1400 kabuli were evaluated for yield losses arising from pod borer (Helicoverpa armigera) infestation under rainfed conditions by spraying half the plots to prevent pod borer infestation and allowing the other half to be infested. From these lines, 82 were selected for further detailed evaluation of Helicoverpa resistance and drought resistance under irrigated and rainfed conditions. The yield losses from Helicoverpa damage varied from 10 to 33% depending on the chickpea type and the growing environment. Spreading types were more susceptible to Helicoverpa damage than erect types, as were kabuli types compared to desi types. Yield losses due to Helicoverpa infestation were always greater in the irrigated than in the rainfed materials. Terminal drought reduced yields by 13–37% depending on plant type. The yields in the kabuli c“hickpea lines were more severely reduced than were the desi types, due to a greater reduction in the number of branches and pods per plant in the kabuli compared to the desi lines. It appears that the extent of pod borer damage varies between the chickpea types, and that desi types have greater drought resistance than kabuli ones. These characteristics should be informative for the population improvement of chickpea for environments in which terminal drought and Helicoverpa damage occur frequently.

The cryopreservation of embryonic axes of two wild and endangered species, Citrusmacroptera Mont. and C. latipes Tanaka, was attempted using air desiccation–freezing, vitrification and encapsulation–dehydration. Successful cryopreservation was achieved in both the species using these three methods. However, the two species responded differently to: the rate of drying and the degree of tolerance to desiccation following air desiccation–freezing; the response to loading duration following vitrification; and to the sucrose concentration during pre-culture following encapsulation–dehydration. C. macroptera was more tolerant to desiccation and freezing than C. latipes with recovery rates of, respectively, 87% and 64%. Recovery from encapsulation–dehydration was 62% for C. macroptera and 45% for C. latipes. In both species, the vitrification protocol gave a significant improvement in recovery rates: 92% and 77% for C. macroptera and C. latipes, respectively. The air desiccation–freezing protocol being a simple and practical technique is recommended for the cryopreservation of these two species.

A regional (Oceania) core collection for taro germplasm has been developed based on phenotypic and molecular characterization. In total, 2199 accessions of taro germplasm have been collected by TaroGen (Taro Genetic Resources: Conservation and Utilisation) from 10 countries in Oceania: Papua New Guinea, Solomon Islands, Vanuatu, New Caledonia, Fiji, Palau, Niue, Tonga, Cook Islands and Samoa. Our objective was to select 10% from each country to contribute to a regional core. The larger collections from Papua New Guinea, Vanuatu and New Caledonia were analysed based on phenotypic characters, and a diverse subset representing 20% of these collections was fingerprinted. A diverse 20% subsample was also taken from the Solomon Islands. All accessions from the other six countries were fingerprinted. In total, 515 accessions were genotyped (23.4% overall) using taro specific simple sequence repeat (SSR) markers. DNA fingerprint data showed that great allelic diversity existed in Papua New Guinea and the Solomon Islands. Interestingly, rare alleles were identified in taros from the Solomon Islands province of Choiseul which were not observed in any of the other collections. Overall, 211 accessions were recommended for inclusion in the final regional core collection based on the phenotypic and molecular characterization.