Preliminary Results on Evaluation of Chickpea, Cicer arietinum, Genotypes for Resistance to the Pulse Beetle, Callosobruchus maculatus

The chickpea, Cicer arietinum L. (Fabales: Fabaceae), seeds are vulnerable, both in the field and in storage, to attack by seed-beetles. Beetles of the genus Callosobruchus are major storage pests of chickpea crops and cause considerable economic losses. In the present study, a total of 11 chickpea genotypes including five ‘kabuli’ (Mexican white, Diyar, CA 2969, ILC 8617 and ACC 245) and six ‘desi’ chickpeas (ICC 1069, ICC 12422, ICC 14336, ICC 4957, ICC 4969 and ICC 7509) were evaluated for resistance to the pulse beetle Callosobruchus maculatus F. (Coleoptera: Bruchidae). Resistance was evaluated by measuring percent damage to seeds. Damage to seeds by C. maculatus was manifested by the round exit holes with the ‘flap’ of seed coat made by emerging adults. Of the 11 genotypes tested, only one (ICC 4969) exhibited a complete resistance to C. maculatus in both free-choice and no-choice tests; no seed damage was found over the test period. In general, the ‘desi’ chickpeas were more resistant to C. maculatus than the ‘kabuli’ chickpeas. Among the tested chickpea genotypes, only ICC 4969 can be used as a source of C. maculatus resistance in breeding programmes that could then be grown in organic cultivation free from pesticides

Genetic Patterns of Domestication in Pigeonpea (Cajanus cajan (L.) Millsp.) and Wild Cajanus Relatives

Pigeonpea (Cajanus cajan) is an annual or short-lived perennial food legume of acute regional importance, providing significant protein to the human diet in less developed regions of Asia and Africa. Due to its narrow genetic base, pigeonpea improvement is increasingly reliant on introgression of valuable traits from wild forms, a practice that would benefit from knowledge of its domestication history and relationships to wild species. Here we use 752 single nucleotide polymorphisms (SNPs) derived from 670 low copy orthologous genes to clarify the evolutionary history of pigeonpea (79 accessions) and its wild relatives (31 accessions). We identified three well-supported lineages that are geographically clustered and congruent with previous nuclear and plastid sequence-based phylogenies. Among all species analyzed Cajanus cajanifolius is the most probable progenitor of cultivated pigeonpea. Multiple lines of evidence suggest recent gene flow between cultivated and non-cultivated forms, as well as historical gene flow between diverged but sympatric species. Evidence supports that primary domestication occurred in India, with a second and more recent nested population bottleneck focused in tropical regions that is the likely consequence of pigeonpea breeding. We find abundant allelic variation and genetic diversity among the wild relatives, with the exception of wild species from Australia for which we report a third bottleneck unrelated to domestication within India. Domesticated C. cajan possess 75% less allelic diversity than the progenitor clade of wild Indian species, indicating a severe “domestication bottleneck” during pigeonpea domestication

Induced autotetraploidy in chickpea (Cicer arietinum L.)

In chickpea, out of three colchicine concentrations and two treatment durations used (combinations of 0.25, 0.05, 0.025% colchicine and 4 and 6 h duration), seed treatment with 0.25% for 4 h proved to be the most effective in producing autotetraploids. Colchicine treatment on seedlings failed. The induced tetraploidy was accompanied by larger leaves, flowers, stomata, pollen grains and seeds. Mean percentage stainable pollen and podset were reduced, but some plants had relatively normal meiosis and produced as many pods as the diploid parent, indicating the potential of induced autotetraploids in chickpea improvement

Complex problems require complex solutions: the utility of social quality theory for addressing the Social Determinants of Health

Extent: 9p.Background: In order to improve the health of the most vulnerable groups in society, the WHO Commission on Social Determinants of Health (CSDH) called for multi-sectoral action, which requires research and policy on the multiple and inter-linking factors shaping health outcomes. Most conceptual tools available to researchers tend to focus on singular and specific social determinants of health (SDH) (e.g. social capital, empowerment, social inclusion). However, a new and innovative conceptual framework, known as social quality theory, facilitates a more complex and complete understanding of the SDH, with its focus on four domains: social cohesion, social inclusion, social empowerment and socioeconomic security, all within the same conceptual framework. This paper provides both an overview of social quality theory in addition to findings from a national survey of social quality in Australia, as a means of demonstrating the operationalisation of the theory. Methods: Data were collected using a national random postal survey of 1044 respondents in September, 2009. Multivariate logistic regression analysis was conducted. Results: Statistical analysis revealed that people on lower incomes (less than $45000) experience worse social quality across all of the four domains: lower socio-economic security, lower levels of membership of organisations (lower social cohesion), higher levels of discrimination and less political action (lower social inclusion) and lower social empowerment. The findings were mixed in terms of age, with people over 65 years experiencing lower socio-economic security, but having higher levels of social cohesion, experiencing lower levels of discrimination (higher social inclusion) and engaging in more political action (higher social empowerment). In terms of gender, women had higher social cohesion than men, although also experienced more discrimination (lower social inclusion). Conclusions: Applying social quality theory allows researchers and policy makers to measure and respond to the multiple sources of oppression and advantage experienced by certain population groups, and to monitor the effectiveness of interventions over time.Paul R Ward, Samantha B Meyer, Fiona Verity, Tiffany K Gill and Tini CN Luon

Genetic diversity and population structure of Ascochyta rabiei from the western Iranian Ilam and Kermanshah provinces using MAT and SSR markers

Knowledge of genetic diversity in A. rabiei provides different levels of information that are important in the management of crop germplasm resources. Gene flow on a regional level indicates a significant potential risk for the regional spread of novel alleles that might contribute to fungicide resistance or the breakdown of resistance genes. Simple sequence repeat (SSR) and mating type (MAT) markers were used to determine the genetic structure, and estimate genetic diversity and the prevalence of mating types in 103 Ascochyta rabiei isolates from seven counties in the Ilam and Kermanshah provinces of western Iran (Ilam, Aseman abad, Holaylan, Chardavol, Dareh shahr, Gilangharb, and Sarpul). A set of 3 microsatellite primer pairs revealed a total of 75 alleles; the number of alleles varied from 15 to 34 for each marker. A high level of genetic variability was observed among A. rabiei isolates in the region. Genetic diversity was high (He = 0.788) within populations with corresponding high average gene flow and low genetic distances between populations. The smallest genetic distance was observed between isolates from Ilam and Chardavol. Both mating types were present in all populations, with the majority of the isolates belonging to Mat1-1 (64%), but within populations the proportions of each mating type were not significantly different from 50%. Results from this study will be useful in breeding for Ascochyta blight-resistant cultivars and developing necessary control measures

Pigeonpea

Pigeonpea was labeled as an orphan crop but is now a trendy and pacesetter, with ample genetic and genomic information becoming available in recent times. It is now possible to cross wild relatives not only from the Cajanus group placed in the secondary and tertiary gene pool but also the related genera placed in the quaternary gene pool. This is no small achievement for a legume which is an important crop of Asia and Africa and plays a major role in the diet of majority of the people of this region. The need of the hour is further committed research on wide crosses in pigeonpea

Antixenosis and antibiosis mechanisms of resistance to pod borer, Helicoverpa armigera in wild relatives of chickpea, Cicer arietinum

The noctuid pod borer, Helicoverpa armigera is one of the most damaging pests of chickpea, Cicer arietinum. The levels of resistance to H. armigera in the cultivated chickpea are low to moderate, but the wild relatives of chickpea have exhibited high levels of resistance to this pest. To develop insect-resistant cultivars with durable resistance, it is important to understand the contribution of different components of resistance, and therefore, we studied antixenosis and antibiosis mechanisms of resistance to H. armigera in a diverse array of wild relatives of chickpea. The genotypes IG 70012, PI 599046, IG 70022, PI 599066, IG 70006, IG 70018 (C. bijugum), ICC 506EB, ICCL 86111 (cultivated chickpea), IG 72933, IG 72953 (C. reticulatum), IG 69979 (C. cuneatum) and IG 599076 (C. chrossanicum) exhibited non preference for oviposition by the females of H. armigera under multi-choice, dual-choice and no-choice cage conditions. Based on detached leaf assay, the genotypes IG 70012, IG 70022, IG 70018, IG 70006, PI 599046, PI 599066 (C. bijugum), IG 69979 (C. cuneatum), PI 568217, PI 599077 (C. judaicum) and ICCW 17148 (C. microphyllum) suffered significantly lower leaf damage, and lower larval weights indicating high levels of antibiosis than on the cultivated chickpea. Glandular and non-glandular trichomes showed negative correlation with oviposition, while the glandular trichomes showed a significant and negative correlation with leaf damage rating. Density of non-glandular trichomes was negatively correlated with larval survival. High performance liquid chromatography (HPLC) fingerprints of leaf surface exudates showed a negative correlation of oxalic acid with oviposition, but positive correlation with malic acid. Both oxalic acid and malic acid showed a significant negative correlation with larval survival. The wild relatives exhibiting low preference for oviposition and high levels of antibiosis can be used as sources of resistance to increase the levels and diversify the basis of resistance to H. armigera in cultivated chickpea

Modern Genomic Tools for Pigeonpea Improvement: Status and Prospects

Pigeonpea owing to its ability to sustain harsh environment and limited input/water requirement remains an excellent remunerative crop in the face of increasing climatic adversities. With nearly 70% share in global pigeonpea production, India is the leading pigeonpea producing country. Since the mid-1900s, constant research efforts directed to improve yield and resistance levels of pigeonpea have resulted in the development and deployment of several commercially accepted cultivars in India, accommodating into diverse agro-climatic zones. However, the crop productivity needs incremental improvements in order to meet the growing nutritional demands, especially in developing countries like India where pigeonpea forms a dominant part of vegetarian diet. Empowering crop improvement strategies with genomic tool kit is imperative to attain the project gains in crop yield. In the context, adoption of next-generation sequencing (NGS) technology has helped establish a wide range of genomic resources to support pigeonpea breeding, and the existing molecular tool kit includes genome-wide genetic markers, transcriptome/genome assemblies, and candidate genes/QTLs for target traits. Similarly, availability of whole mitochondrial genome sequence and derived DNA markers is immensely relevant in order to furthering the understanding of cytoplasmic male sterility (CMS) system and hybrid breeding. This chapter covers the progress of developing modern genomic resources in pigeonpea and highlights their vital role in designing future crop breeding schemes