Crop wild relatives are important components of agro-ecosystems as potential gene contributors for crop improvement programmes. Cajanus scarabaeoides (L.) Thou., a pigeonpea wild relative is crossable with cultivated pigeonpea and possesses several beneficial traits. Hundred accessions conserved at the ICRISAT genebank were characterized for 13 quantitative and ten qualitative traits to assess the diversity in the collection. Highly significant genotypic variance for leaflet length, days to 5% maturity, seeds per pod, 100-seed weight, seed protein content and trichome density and length was observed. All C. scarabaeoides accessions used in the present study are the best sources for extra early ( < 80 d to 50% flowering) and early maturity (80–100 d to 50% flowering). Eight accessions (ICP 15692, ICP 15696, ICP 15698, ICP 15699, ICP 15712, ICP 15719, ICP 15732 and ICP 15758) and the control ICP 15695 have produced more than 92% healthy pods per plant and higher number of seed per pod (4–6 seeds). Accessions in cluster 2, 3 and 4 with low mean values for days to 50% flowering were found as the best sources for early flowering and maturity. Accessions in cluster 2 and 3 for seeds per pod and cluster 2 for healthy pods per plant were found as promising sources for use in crop improvement. Mean diversity over all clusters was highest (H= 0.57 ± 0.01) for seeds per pod and lowest for days to 50% flowering (0.48 ± 0.02). Significant negative correlation between pods per raceme and healthy pods per plant ( − 0.213) indicated high pod damage in racemes having more pods. Trichome length had highly significant negative association with healthy pods per plant ( − 0.293). The probability map generated using FloraMap, a GIS tool, revealed the occurrence of C. scarabaeoides quite close to the origin and dispersal of pigeonpea. The probability (>75%) map identified a total of 118 provinces covering 790 districts in Bangladesh, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippines, Thailand and Vietnam as geographical gaps in the collection. Complete passport data including location coordinates should be collected while collecting the germplasm to analyze the spatial aspects of species distribution.

Genebanks serve as a rich source of diversity that can be exploited for crop improvement. However, large numbers of accessions usually have to be evaluated to find material with the characters of interest, and therefore, enhanced trait information can facilitate the more efficient selection of accessions by users. In this study, we report on the distribution of resistances to 28 races of downy mildew among 1223 genebank accessions of cultivated lettuce (Lactuca sativa L.) and 14 related wild species. Due to modern plant breeding, the overall level of resistance of cultivars released after 1950 appears to have increased two- to three-fold compared with varieties from earlier periods. Although fully resistant reactions could be observed among the accessions of cultivated lettuce for each of the 28 investigated races, the resistance probability was more than two-fold higher on average for accessions from the wild gene pool. In general, species of the primary gene pool appeared less resistant than those of the secondary or tertiary gene pool. Probabilities for examined Lactuca species ranged from 0.29 for L. serriola to 1.00 for L. perennis compared with 0.19 for cultivated lettuce, with lower overall resistance probabilities observed only for L. altaica, L. dregeana and L. tenerrima. For L. serriola, the closest relative of cultivated lettuce and the wild species with the highest number of examined accessions, resistance probabilities to each of the investigated downy mildew races were relatively high for populations originating from Eastern Europe and Northern Asia.

Lens culinaris Medik. ssp. culinaris is the only cultivated species in the genus Lens. Intensive selection pressure to develop new cultivars, a narrow genetic base, co-evolution of pathogens to partially resistant cultivars and other factors have accelerated susceptibility to different fungal diseases in this species. Few sources for resistance to stemphylium blight (SB) caused by Stemphylium botryosum Wallr. exist among commercial lentil cultivars. A total of 70 accessions were selected from seven species of the genus Lens to screen for SB resistance. The L. culinaris accessions were screened in four different environments, and the accessions of Lens ervoides, L. culinaris ssp. orientalis, Lens tomentosus,Lens nigricans, Lens odemensis and Lens lamottei in growth chamber or greenhouse experiments to identify resistance sources for potential use in lentil breeding. A highly aggressive isolate of SB was used as an inoculum to screen them under controlled conditions. Lentil cultivars ‘Eston’ (resistant) and ‘CDC Glamis’ (susceptible) were used as checks with consistent results in all experiments. Most of the L. culinaris accessions were susceptible to SB, whereas more than 70% of the wild lentil accessions had disease severity scores equal to or significantly lower than that of the SB-resistant check ‘Eston’. Some wild species accessions previously identified with resistance to anthracnose (Colletotrichum truncatum) and ascochyta blight (Ascochyta lentis) were also highly resistant to SB. The highest frequency of resistance to SB was found in L. lamottei followed by L. ervoides of the secondary gene pool. These sources can potentially be used to develop new commercial cultivars with multiple or single disease resistance.

The study of the genetic structure of cultivated plant populations maintained by farmers is of great importance for evolutionary and conservation biology. Such studies help understand the bases of crop evolution and conservation in relation to farmers' practices. In this study, we assessed the genetic structure underlying landrace diversity of dry-season sorghum. This crop constitutes a historical model of innovation developed by farmers to extend sorghum cultivation to the dry season. Two types of dry-season sorghum are cultivated. We aimed to assess the link between farmers' taxonomy and molecular genetic structure. We collected both types of dry-season sorghum in two villages of northern Cameroon which represented 20 landraces. These landraces were genotyped using eight polymorphic microsatellite markers. This study compared two clustering methods: a Bayesian method (STRUCTURE) which is based on explicit genetic assumptions and the discriminant analysis of principal component method. The latter, more recently proposed, is based on the combination of principal component analysis and discriminant analysis. We noticed a general congruence between these two methods. We also used both methods to infer the genetic structure of our sample. Our results showed strong genetic structuring of the landraces, with K= 14 genetic clusters. We then analysed the fit between farmers' taxonomy and genetic structure. The data suggested that each type and each landrace corresponds to a given genetic entity. This pattern was robust across both villages, despite differences in cultural practices.

Bananas and plantains (Musa spp.) constitute staple food for over 20 million people in Democratic Republic of Congo (DRC). Since 1960, DRC is considered as a secondary centre of plantain diversification with few unknown accessions kept in the INERA-Mulungu genebank. Through similarity coefficients, cluster (unweighted pair group method with arithmetic mean, single, complete, sequential, agglomerative, hierarchical and nested design/clustering procedure) and/or multivariate analyses, numerical morpho-taxonomy has established that this diversity is composed of 37 different accessions. Each accession expressed 98 characters among the 401 possible character states, thus providing 39,298 feature patterns (data points). The 98 characters included 32 vegetative and 66 male and female inflorescences. The accessions were clustered into three genomic groups (AAA, AAB and AABB). Subjective classification ascertained nine subgroups: AAB-Silk, AAB-Pome, AAB-Plantain, AABB-Pisang Awak, AAA-Cavendish, AAA-Ibota, AAA-Gros Michel, AAA-Green-Red and AAA-Lujugira-Mutika. Three subgroups were further divided into nine clone sets which consisted of: Dwarf and Giant Cavendish, French and Horn Plantains, and Musakala, Nfuuka, Nakitembe, Nakabululu and Beer/Mbidde within Lujugira-Mutika. Numerical morpho-taxonomy effectively indicated a relationship between the DRC and Tanzania's Musa diversity. For example, the accessions ‘Kamaramasengi’ and ‘Isangi’ were found to be similar to ‘Kisukari’ (AAB-Silk) and ‘Ngego I’ (AAB-French) common in the Tanzanian Southern Highland. Likewise, the accessions Kimalindi-fupi, Kimalindi-ndefu and Jamaica of Tanzania were duplicates of Bakurura (Kigurube), Cavendish of Butuza and Gros Michel in DRC, respectively. Moreover, numerical morpho-taxonomy confirmed the pedigree of AAB-Prata (Cibwalo) in FHIA 17 and FHIA 23 and the closeness of the ancestors of Yangambi Km5 and Gros Michel. Furthermore, numerical morpho-taxonomy established AA-Mshale malembo as one of the AAA-Lujugira-Mutika parents. Molecular investigations are finally required to confirm the genomes.

The National Bureau of Plant genetic Resources (NBPGR), New Delhi carries out the registration of unique crop germplasm in order to protect the intrinsic intellectual property as well as to facilitate greater utilization of germplasm in crop improvement programmes. It is therefore imperative to enhance access to information on registered crop germplasm. Here, we present a concept of a search engine that can suffice dual functions of a Web-based and portable search application. The concept entails converting raw data through a series of transformations from a Microsoft-Excel to eXtensible Markup Language (XML) data format. XML data initialized on compatible Web browsers are then queried for the search term based on a looping regular expression matching. The results are then loaded onto the browser in a tabulated output. The concept is implemented in the form of ‘Inventory of Registered Crop Germplasm’ on the Web as well as on a portable memory (compact disk or flash drive). The portable search engine works with minimal hardware and software requirements to enable its widespread utility to ensure greater access to information on registered crop germplasm. The portable search engine can be obtained from the NBPGR, New Delhi and the Web-based search engine can be accessed at http://www.nbpgr.ernet.in/IRCG/index.htm.

Extensive studies of genetic diversity and population structure important for conservation of wild sorghum are yet lacking in Ethiopia, the centre of origin for cultivated sorghum. To assess both genetic diversity and the probability of gene flow between wild and cultivated types, collections of wild Sorghum bicolor were made from regions in Ethiopia where wild and cultivated sorghum coexist. Morphological data were recorded in situ for both quantitative and qualitative characters from 30 populations in five diverse geographical regions and eight agroecologies. High phenotypic diversity was observed among the wild and weedy sorghum populations. The overall standardized Shannon–Weaver diversity index (H′), computed from the frequencies of all qualitative traits, ranged from 0.47 to 0.98 with an average value of 0.76. Moreover, warm semi-arid lowland (SA2) agroecologies, which contain Tigray populations, supported the highest diversity for these traits. Subspecies verticilliflorum and drummondii (the two major subspecies of wild S. bicolor) were observed in diverse habitats throughout northern and central Ethiopia. In some areas, weedy types showed domestication traits including the absence of awns and reduced seed shattering. The existence of morphologically intermediate forms indicates that gene flow between cultivated and wild forms has likely occurred. Deployment of transgenic crop sorghum, therefore, would pose a distinct risk for transgene movement into wild Ethiopian populations.

In order to utilize germplasm resources more efficiently for peanut (Arachis hypogaea L.) genetic improvement, a core collection of 576 accessions and a primary mini core collection of 298 accessions were developed previously from a collection of 6839 cultivated peanut lines stored at the Oil Crops Research Institute of Chinese Academy of Agricultural Sciences at Wuhan. For an efficient evaluation and characterization of the most useful agronomic and disease-resistant traits, an even smaller collection of peanut accessions that represent a spectrum of phenotypes could be more desirable. For this reason, a mini-mini core collection with 99 accessions from the core accessions was developed based on the analysis of 21 morphological traits. It was demonstrated that there were no significant differences between the core and mini-mini core collections in 20 out of the 21 morphological traits studied. Further, the mini-mini core collection captured the ranges of all of the 21 traits displayed in the core collection. The newly developed mini-mini core collection was assessed for resistance to bacterial wilt disease caused by Ralstonia solanacearum. Two accessions showing a high level of resistance to bacterial wilt were identified, demonstrating the usefulness of the mini-mini core collection. The mini-mini-core collection provides a more efficient means of germplasm evaluation and will be resequenced as part of the International Peanut Genome Consortium sequencing project at the UC-Davis Genome Center.

A detailed survey along the coastal regions of Southern India revealed the occurrence of seven Pandanus species, viz. P. kaida Kurz., P. odorifer (Forssk.) Kuntz., P. canaranus Warb., P. furcatus Roxb., P. thwaitesii Mart., P. foetidus Roxb and a new species P. palakkadensis Nadaf, Zanan & Wakte. The fragrance of staminate inflorescences of these species was compared with the fragrance of commercial staminate inflorescences of P. odorifer. P. thwaitesii,P. kaida and P. palakkadensis recorded comparable fragrance with that of P. odorifer. The study reveals the fragrance potential of these species, which could be exploited commercially for extraction of essential oil.

Anthocyanin indexes, quercetin, kaempferol and myricetin may provide industry with potential new medicines or nutraceuticals. Velvetleaf (Abutilon theophrasti Medik) leaves from 42 plant introductions (PI) were analyzed for anthocyanin indexes while both leaves and fruit were used for quercetin, kaempferol and myricetin concentration analysis by reverse-phase high performance liquid chromatography. Leaf anthocyanin indexes ranged from 6.15 to 11.25 among PI. Leaf quercetin and kaempferol concentrations ranged from 1.50 to 4.79 mg/g and 0.43 to 2.17 mg/g, respectively. Fruit quercetin, kaempferol and myricetin concentrations ranged from 0.061 to 0.266 mg/g, 0.054 to 0.734 mg/g, and 0 to 35.87 μg/g, respectively. Significant differences in leaf weight were also observed. Significant correlations were found between several traits. This information regarding anthocyanin indexes, quercetin, kaempferol and myricetin concentrations will be useful for velvetleaf cultivar development. Breeders and other scientists could use this germplasm that contains high concentrations of anthocyanins, quercetin, kaempferol and myricetin to develop new medicines or nutraceuticals from an extremely useful weedy species.

Morinda reticulata Gamble and Morinda umbellata Linn. (Rubiaceae) are medicinally important climbers distributed as a mixed population in southern Western Ghats of India. A close morphological resemblance of these two species misleads the harvester in the identification of plant parts for preparation of herbal medicines. Though both species contain anthraquinone derivatives and share common medicinal properties for treating stomach disorders, each of these species has unique curative properties for treating selective diseases. Conventional methods are not reliable for identification of these species due to similarities in morphology. Thus, misidentification often leads to the deterioration of the quality of medicines. Thus, authentication utilizing conserved gene sequences in the chloroplast genome of these two Morinda spp. has been attempted for precise identification. Here we report the use of two barcoding genes (maturase kinase and ribulose 1,5-bisphosphate carboxylase large subunit) to distinguish M. reticulata and M. umbellata based on single nucleotide polymorphism. The present findings can be used for authenticating leaf samples of M. reticulata and M. umbellata.