Rapid generation advance (RGA) in chickpea to produce up to seven generations per year and enable speed breeding

This study was aimed at developing a protocol for increasing the number of generation cycles per year in chickpea (Cicer arietinum L.). Six accessions, two each from early (JG 11 and JG 14), medium (ICCV 10 and JG 16), and late (CDC-Frontier and C 235) maturity groups, were used. The experiment was conducted for two years under glasshouse conditions. The photoperiod was extended to induce early flowering and immature seeds were germinated to further reduce generation cycle time. Compared to control, artificial light caused a reduction in flowering time by respectively 8–19, 7–16, and 11–27 days in early-, medium-, and late-maturing accessions. The earliest stage of immature seed able to germinate was 20–23 days after anthesis in accessions of different maturity groups. The time period between germination and the earliest stage of immature seed suitable for germination was considered one generation cycle and spanned respectively 43–60, 44–64, and 52–79 days in early-, medium-, and late-maturing accessions. However, the late-maturing accession CDCFrontier could not be advanced further after three generation cycles owing to the strong influence of photoperiod and temperature. The mean total number of generations produced per year were respectively 7, 6.2, and 6 in early-, medium-, and late-maturing accessions. These results have encouraging implications for breeding programs: rapid progression toward homozygosity, development of mapping populations, and reduction in time, space and resources in cultivar development (speed breeding)

Botany of Chickpea

Chickpea is one of the important food legumes cultivated in several countries. It originated in the Middle East (area between south-eastern Turkey and adjoining Syria) and spread to European countries in the west to Myanmar in the east. It has several vernacular names in respective countries where it is cultivated or consumed. Taxonomically, chickpea belongs to the monogeneric tribe Cicereae of the family Fabaceae. There are nine annuals and 34 perennial species in the genus Cicer. The cultivated chickpea, Cicer arietinum, is a short annual herb with several growth habits ranging from prostrate to erect. Except the petals of the flower, all the plant parts are covered with glandular and non-glandular hairs. These hairs secrete a characteristic acid mixture which defends the plant against sucking pests. The stem bears primary, secondary and tertiary branches. The latter two branch types have leaves and flowers on them. Though single leaf also exists, compound leaf with 5–7 pairs of leaflets is a regular feature. The typical papilionaceous flower, with one big standard, two wings and two keel petals (boat shaped), has 9 + 1 diadelphous stamens and a stigma with 1–4 ovules. Anthers dehisce a day before the flower opens leading to self-pollination. In four weeks after pollination, pod matures with one to three seeds per pod. There is no dormancy in chickpea seed. Based on the colour of chickpea seed, it is desi type (dark-coloured seed) or kabuli type (beige-coloured seed). Upon sowing, germination takes a week time depending on the soil and moisture conditions

Knowledge Acquisition by Networks of Interacting Agents in the Presence of Observation Errors

In this work we investigate knowledge acquisition as performed by multiple agents interacting as they infer, under the presence of observation errors, respective models of a complex system. We focus the specific case in which, at each time step, each agent takes into account its current observation as well as the average of the models of its neighbors. The agents are connected by a network of interaction of Erd\H{o}s-Renyi or Barabasi-Albert type. First we investigate situations in which one of the agents has a different probability of observation error (higher or lower). It is shown that the influence of this special agent over the quality of the models inferred by the rest of the network can be substantial, varying linearly with the respective degree of the agent with different estimation error. In case the degree of this agent is taken as a respective fitness parameter, the effect of the different estimation error is even more pronounced, becoming superlinear. To complement our analysis, we provide the analytical solution of the overall behavior of the system. We also investigate the knowledge acquisition dynamic when the agents are grouped into communities. We verify that the inclusion of edges between agents (within a community) having higher probability of observation error promotes the loss of quality in the estimation of the agents in the other communities.Comment: 10 pages, 7 figures. A working manuscrip

Pulses Value Chain Development for Achieving Food and Nutrition Security in South Asia: Current Status and Future Prospects

Pulses are important crops in the cropping systems of several developing countries in Asia, Africa, and Latin America. In South Asia, pulses account for 15% of the cropped area and are grown mainly on less fertile and marginal lands as intercrops with cereals and oilseeds. Besides being environmentally friendly (by fixing soil nitrogen), pulses contribute towards food security, and more importantly nutrition security, particularly for low-income consumers. South Asia accounts for 24% of global pulse production with India accounting for 90% of the production. However, since the seventies per capita pulse consumption has been declining in South Asia, although since 2008 it started trending up at a slow pace. To meet the growing deficit of pulses its global trade increased rapidly from 7.2 million tonnes in 2000 to 17 million tonnes in 2016. To meet the export demand, pulse production diversified, with developed countries emerging as the main exporters while developing countries were the main importers. The exceptions were South Eastern Asia (Myanmar) and Eastern Africa, which also emerged as important exporters. South Asia accounted for 49% of global pulse imports in 2016 with India accounting for two thirds of the imports to the region. Severe crisis of pulses in the recent past led to the path-breaking policy interventions in South Asia, especially in India viz., increasing availability of quality seeds, enhancement in minimum support price (MSP), assured procurement by government agencies and maintenance of buffer stock of pulses. These interventions attracted farmers towards growing pulses and played a key role in increasing the pulses production. In general, Chickpea, Pigeonpea, Green gram (mungbean) Black gram (urdbean), Lentil, Grass pea, and Soybean fall under the pulses group in South Asia. Due to the gap between supply and demand for pulses conumption, the price of pulses increased sharply over the years leading to import of pulses to fulfill the local requirement. A higher consumer demand was observed for the imported products mainly due to the quality and low price. Though pulses are low input crops, cost of production and gross return of pulses have shown an increasing trend over the past. The importance of mechanization in pulse crops is highly emphasized to reduce the cost of production. Productivity constraints of insect pests and diseases in the field and storage conditions are perceived as being very important. Most of the South Asian 2 countries are placing high priority on modernization of agricultural practices, improvement of productivity and competitiveness in marketing in domestic and international markets while enhancing the value addition and product diversification to generate new income and viable employment opportunities

Achievements and challenges in improving nutritional quality of chickpea

Chickpea (Cicer arietinum L.) grains are an excellent source of protein, carbohydrates, minerals, vitamins, dietary fibre, folate, β-carotene and health promoting fatty acids. Their consumption provides consumers with a variety of nutritional and health benefits. Limited breeding efforts have been made on nutritional quality traits of chickpea. Potential exists for further enhancing contents of protein, minerals (iron and zinc), folate and β-carotene and reducing the contents of flatulence causing raffinose family of oligosaccharides (RFOs). The desi types account for about 80% to 85% of the global chickpea area and largely grown in South Asia, Eastern Africa, and Australia and mainly consumed in South Asia. Though the total chickpea area under kabuli type is less (15 to 20%), the production and consumption of kabuli type is globally more wide spread than the desi types. Chickpeas are mainly used for human consumption and a very small proportion as animal feed. The dry chickpea grains are used whole (after soaking and/or cooking, roasting or parching) or dehulled to make splits (dal) or ground to produce flour (besan). The soaked/cooked chickpea grains are used in salads, making vegetable curries (Chhole) and several other preparations, such as falafel (deep fried balls or patties) and hummus (chickpea dip or spread). The chickpea flour is used in making a wide variety of snack foods, soups, sweets, and condiments besides being mixed with wheat flour to make Indian bread (roti or chapati). Invariably, splits (dal) and flour are made from desi type, while hummus is made from kabuli type. Chickpea leaves are used as leafy vegetable and immature green grains are eaten raw or after roasting and also used as vegetable

Genetic studies for seed size and grain yield traits in kabuli chickpea

Seed size, determined by 100-seed weight, is an important yield component and trade value trait in kabuli chickpea. In the present investigation, the small seeded kabuli genotype ICC 16644 was crossed with four genotypes (JGK 2, KAK 2, KRIPA and ICC 17109) and F1, F2 and F3 populations were developed to study the gene action involved in seed size and other yield attributing traits. Scaling test and joint scaling test revealed the presence of epistasis for days to first flower, days to maturity, plant height, number of pods per plant, number of seeds per plant, number of seeds per pod, biological yield per plant, grain yield per plant and 100-seed weight. Additive, additive × additive and dominance × dominance effects were found to govern days to first flower. Days to maturity and plant height were under the control of both the main as well as interaction effects. Number of seeds per pod was predominantly under the control of additive and additive × additive effects. For grain yield per plant, additive and dominance × dominance effects were significant in the cross ICC 16644 × KAK 2, whereas, additive × additive effects were important in the cross ICC 16644 × JGK 2. Additive, dominance and epistatic effects influenced seed size. The study emphasized the existence of duplicate epistasis for most of the traits. To explore both additive and non-additive gene actions for phenological traits and yield traits, selection in later generations would be more effective

Impact of Genomics on Chickpea Breeding

Chickpea is an economical source of vegetable protein for the poor living in the semi-arid regions globally. As a consequence of climate change and increasing climate variability, the incidences of drought and heat stresses and severity of some diseases, such as dry root rot and collar rot, have increased in chickpea crop, resulting in poor and unstable yields. By improving the efficiency of crop breeding programs, climate resilient varieties with traits desired by the farmers, industries and consumers can be developed more rapidly. Excellent progress has been made in the development of genomic resources for chickpea in the recent past. Several national and international chickpea breeding programs have started utilizing these genomic resources and tools for genetic improvement of complex traits. One of such examples includes the introgression of “QTL-hotspot” containing quantitative trait loci (QTLs) for several drought tolerance-related traits, including root traits, through marker-assisted backcrossing (MABC) for enhancing drought tolerance in popular cultivars. Several drought-tolerant introgression lines with higher yield as compared to the popular cultivars have been identified. Multi-parent advanced generation intercross (MAGIC) populations developed from using 8 parents created large genetic diversity consequently several promising lines. Marker-assisted recurrent selection (MARS) has also been explored for yield improvement in chickpea. Development of diagnostic markers or the identification of candidate genes for several traits is essential for greater use of genomic resources in chickpea improvement

Inheritance of protein content and its relationships with seed size, grain yield and other traits in chickpea

Chickpea (Cicer arietinum L.), the second largest grown pulse crop of the world, is an important source of protein for millions of people, particularly in South Asia. Development of chickpea cultivars with further enhanced levels of protein is highly desired. This study was aimed at understanding the genetic control of protein content and its association with other traits so that suitable breeding strategies can be prepared for development of high protein content cultivars. A high protein (29.2 %) desi chickpea line ICC 5912 with pea-shaped small seed, grey seed coat and blue flower was crossed with a low protein (20.5 %) kabuli line ICC 17109 with owl’s head shaped large seed, beige seed coat, and white flower. The F2 population was evaluated under field conditions and observations were recorded on protein content and other traits on individual plants. The protein content of F2 segregants showed continuous distribution suggesting that it is a quantitative trait controlled by multiple genes. The blue flowered segregants had pea shaped seed with grey seed coat, while the white flowered segregants had owl’s head shaped seed with beige seed coat indicating pleiotropic effects of gene(s) on these traits. On an average, blue flowered segregants had smaller seed, lower grain yield per plant and higher protein content than the pink flowered and the white flowered segregants. The protein content was negatively correlated with seed size (r = −0.40) and grain yield per plant (r = −0.18). Thus, an increment in protein content is expected to have a negative effect on seed size and grain yield. However, careful selection of transgressive segregants with high protein content along with moderate seed size and utilizing diverse sources of high protein content will be usefull in developing chickpea cultivars with high protein content and high grain yield

MAGIC lines in chickpea: development and exploitation of genetic diversity

In chickpea a multi-parent advanced generation intercross (MAGIC) population was developed using eight parents that are improved varieties and widely adaptable breeding lines. The main objective was to enhance the genetic diversity and bring novel alleles for developing superior chickpea varieties. The development scheme involved a sequence of 28 two-way, 14 four-way and 7 eight-way crosses, followed by bulking of final F1 plants. From F2 generation onwards single plants were grown as progenies and advanced to F8 by single seed descent method. The finally developed 1136 MAGIC lines were phenotyped under rainfed (RF) and irrigated (IR) conditions for 2 years (2013 and 2014) under normal season, and one year under heat stress (HS) condition (summer-2014) in field to estimate the genetic diversity created among these lines. Under RF-2014, RF-2013, IR-2014, IR-2013 and S-2014 seasons 46, 62, 83, 50 and 61 lines showed significantly higher grain yield than the best parent, respectively. Similarly, 23 and 19 common lines were identified under RF and IR conditions over two years and no common line was identified between RF/IR and HS conditions. Preliminary evaluation showed a large variation among MAGIC lines for flowering time (34–69 days), maturity (80–120 days), plant height (23.3–65 cm), grain yield (179–4554 kg/ha), harvest index (0.10–0.77) and 100 seed weight (10–45 g) under RF and IR conditions. Several genotypes with higher grain yield than the best check under heat stress were identified. These MAGIC lines provide a useful germplasm source with diverse allelic combinations to global chickpea community