Evaluation of New Super-early Pigeonpea Lines for Agronomic Performance and Adaptation in India

Pigeonpea [Cajanus cajan (L.) Millspaugh] is a multi-purpose legume crop used mainly for human consumption in the form of processed split dry peas (dal) or fresh as a vegetable. In addition to food, pigeonpea can also be used for a number of other purposes (ie, feed, fodder, fuel, fertilizer). India is the number one producer and consumer of pigeonpea, but still needs to import around 500,000 tons per year to satisfy the internal demand. Increasing the area under pigeonpea cultivation could contribute to increased production, but this would only be possible by expanding pigeonpea cultivation to non-traditional areas including wider latitudes, higher altitudes and marginal lands, and to fit in the narrow window of time between harvest and planting of important cereal crops

Water-logging: A Forgotten Problem in Pigeonpea

Water-logging is emerging as a pressing concern at the backdrop of climate change in recent years A global report on climate change has projected a 0.5 – 1.2°C rise in temperatures by 2020, resulting in unpredictable and excessive rainGlobally, an area of more than 40 million ha is affected by water-logging In India, an area of 8.53 million ha is affected by water-logging with an estimated loss of >2 million tons of food grains every year

Complementary Effects of Interleukin-15 and Alpha Interferon Induce Immunity in Hepatitis B Virus Transgenic Mice

In chronic hepatitis B (CHB), failure to control hepatitis B virus (HBV) is associated with T cell dysfunction. HBV transgenic mice mirror many features of the human disease, including T cell unresponsiveness, and thus represent an appropriate model in which to test novel therapeutic strategies. To date, the tolerant state of CD8+ T cells in these animals could be altered only by strong immunogens or by immunization with HBV antigen-pulsed dendritic cells; however, the effectors induced were unable to suppress viral gene expression or replication. Because of the known stimulatory properties of alpha interferon (IFN-α) and interleukin-15 (IL-15), this study explored the therapeutic potential of liver-directed gene transfer of these cytokines in a murine model of CHB using adeno-associated virus (AAV) delivery. This combination not only resulted in a reduction in the viral load in the liver and the induction of an antibody response but also gave rise to functional and specific CD8+ immunity. Furthermore, when splenic and intrahepatic lymphocytes from IFN-α- and IL-15-treated animals were transferred to new HBV carriers, partial antiviral immunity was achieved. In contrast to previous observations made using either cytokine alone, markedly attenuated PD-L1 induction in hepatic tissue was observed upon coadministration. An initial study with CHB patient samples also gave promising results. Hence, we demonstrated synergy between two stimulating cytokines, IL-15 and IFN-α, which, given together, constitute a potent approach to significantly enhance the CD8+ T cell response in a state of immune hyporesponsiveness. Such an approach may be useful for treating chronic viral infections and neoplastic conditions

Ensuring the Success of Pigeonpea Hybrids by Focusing on Purity of Parental Lines and Appropriate Management Practices

Pigeonpea [Cajanus cajan (L.) Millsp.] is an important legume crop, grown mainly in the semi-arid tropics of Asia, Africa, Latin America, and the Caribbean. The total world area planted with pigeonpea is 4.6 million ha. India is the number one producer (3.5 million ha) of pigeonpea; despite this, there is not sufficient amount available to meet the nutritional needs of the large and mainly vegetarian resource-poor population and importation of pigeonpea from other countries like Myanmar and parts of Africa is needed to fulfill the country needs. Although dozens of pigeonpea varieties have been released, the productivity of pigeonpea has remained stagnant at around 700 kg ha- 1. This is mainly due to various genetic, management, abiotic, and abiotic constraints. Since the area of pigeonpea cultivation is not likely to be increased, the emphasis moves to break the yield gap and to increase productivity by genetic enhancement of germplasm by incorporating tolerance to biotic and abiotic stresses, and by replacing the traditional varieties with the newly developed options

Integrated physiological and molecular approaches to improvement of abiotic stress tolerance in two pulse crops of the semi-arid tropics

Chickpea (Cicer arietinum L.) and pigeonpea [Cajanus cajan L. (Millsp.)] play an important role in mitigating protein malnutrition for millions of poor vegetarians living in regions of the semi-arid tropics. Abiotic stresses such as excess and limited soil moisture (water-logging and drought), heat and chilling (high and low temperature stresses), soil salinity, and acidity are major yield constraints, as these two crops are grown mostly under rainfed conditions in risk-prone marginal and degraded lands with few or no inputs. Losses due to such stresses vary from 30% to 100% depending on their severity. The literature abounds in basic information concerning screening techniques, physiological mechanisms, and genetics of traits associated with resistance/tolerance to abiotic stresses in these two crops. However, the final outcome in terms of resistant/tolerant varieties has been far from satisfactory. This situation calls for improving selection efficiency through precise phenotyping and genotyping under high-throughput controlled conditions using modern tools of genomics. In this review, we suggest that an integrated approach combining advances from genetics, physiology, and biotechnology needs to be used for higher precision and efficiency of breeding programs aimed at improving abiotic stress tolerance in both chickpea and pigeonpea

Regulation of Lipid Biosynthesis in Saccharomyces cerevisiae by Fumonisin B\u3csub\u3e1\u3c/sub\u3e

The regulation of lipid biosynthesis in the yeast Saccharomyces cerevisiae by fumonisin B1 was examined. Fumonisin B1 inhibited the growth of yeast cells. Cells supplemented with fumonisin B1 accumulated free sphinganine and phytosphingosine in a dose-dependent manner. The cellular concentration of ceramide was reduced in fumonisin B1-supplemented cells. Ceramide synthase activity was found in yeast cell membranes and was inhibited by fumonisin B1. Fumonisin B1 inhibited the synthesis of the inositol-containing sphingo-lipids inositol phosphorylceramide, mannosylinositol phosphorylceramide, and mannosyldiinositol phosphorylceramide. Fumonisin B1 also caused a decrease in the synthesis of the major phospholipids synthesized via the CDP-diacylglycerol-dependent pathway and the synthesis of neutral lipids. The effects of fumonisin B1 and sphingoid bases on the activities of enzymes in the pathways leading to the synthesis of sphingolipids, phospholipids, and neutral lipids were also examined. Other than ceramide synthase, fumonisin B1 did not affect the activities of any of the enzymes examined. However, sphinganine and phytosphingosine inhibited the activities of inositol phosphorylceramide synthase, phosphatidylserine synthase, and phosphatidate phosphatase. These are key enzymes responsible for the synthesis of lipids in yeast. The data reported here indicated that the biosynthesis of sphingolipids, phospholipids and neutral lipids was coordinately regulated by fumonisin B1 through the regulation of lipid biosynthetic enzymes by sphingoid bases

Ensuring Genetic Purity of Pigeonpea Hybrids by Incorporating a Naked-Eye Polymorphic Marker in A and B Lines

To enhance the productivity of pigeonpea [Cajanus cajan (L.) Millspaugh] a hybrid breeding technology, based on the cytoplasmic nuclear male-sterility (CMS) system and partial natural outcrossing, is currently been used. However, there are diffi culties to maintain genetic purity of the hybrids and their parents. The incorporation of an easily identifi able morphological marker (naked eye polymorphism [NEP]) could be used to determine seed purity. The morphological marker selected for this study, obcordate leaf, is not present in cultivated pigeonpea; it is inherited as a single recessive gene and can be observed soon after planting (approx. 6 wk). To incorporate the obcordate leaf shape into hybrid parents, the trait was transferred from the germplasm accession ICP 5529 into male-sterile (A lines) and the corresponding maintainers (B lines). The hybrids derived from crosses involving obcordate leaf A lines and normal leaf fertility restorers (R lines) were fully fertile and had normal lanceolate leaves; thus the difference between A line and hybrids was clear. The use of obcordate leaf as a NEP marker in pigeonpea would contribute to preserve parental line purity and confi rm hybrid status

Effective and economic storage of pigeonpea seed in triple layer plastic bags

Pigeonpea [Cajanus cajan (L.) Millsp.] seed stored in triple layer Purdue Improved Cowpea Storage (PICS) bags for eight months retained germination and seed integrity significantly better than seed stored in traditional gunny bags. PICS bags prevented major damage caused by bruchids (Callosobruchus maculatus F.), while grain stored in gunny bags suffered severe losses. The aflatoxin levels in stored seed were low and not significantly different between the two storage systems. The levels of O2 in PICS bags artificially infested with C. maculatus dropped rapidly during the first month of storage while the levels of CO2 increased. Even in absence of bruchids (noninfested seed) PICS bags preserved seed germination for extended periods of time better than gunny bags; possibly due to the higher and more stable relative humidity inside the PICS bags. Higher seed germination would result in improved plant stands in the field and subsequent higher yields and increased productivity. Thus, PICS bags have shown potential to positively impact the economy of pigeonpea farmers in the semi-arid tropics

GGE biplot based assessment of yield stability, adaptability and mega-environment characterization for hybrid pigeonpea (Cajanus cajan)

GGE biplot methodology is a powerful tool to study relationship among test environments (E), genotypes (G) and genotype-by-environment interaction (GE). Present study was conducted on 10 short-duration genotypes in five test environments for two years, and 16 medium-duration genotypes in six test locations for three years in randomized complete block design with two replications. In short-maturity group three mega-environments (ME) were found—ME1 comprised of Phaltan, Patancheru and Hyderabad1; ME2 and 3 constituted Jalna and Aurangabad, respectively. In scenario of limited resources, Patancheru may be a good testing location for general adaptability of short-duration hybrids, while Aurangabad and Hyderabad1 may be right environments for testing specific adaptation of short-duration cultivars in pigeonpea. ICPH 2433 was a winning genotype in ME1 in terms of high yield and stability. In medium-maturity group, two MEs were observed. Jalna, Jalna 1, Parbhani and Hyderabad grouped together as ME1, while Patancheru and Phaltan formed the second mega-environment (ME2). Parbhani was found to be most representative of all the six test locations. Jalna (ME1) and Phaltan (ME2) produced longest environment vectors, and hence may be regarded as highly discriminating. In mediummaturity group ICPH 2673 was found to be stable and high-yielding genotype for ME

Breeding for Earliness in Pigeonpea: Development of New Determinate and Nondeterminate Lines

Considering the increasing demand for pigeonpea [Cajanus cajan (L.) Millsp.], especially in India, breeders have realized the need to develop high-yielding, super-early maturing (<90 d) lines that could be planted in a wider range of latitudes and/or altitudes to enhance the crop adaptation and to diversify the legume-based cropping systems. The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) initiated a breeding program in 2006 to develop “super-early” (flowering in <50 d) determinate (DT) and nondeterminate (NDT) pigeonpea lines. Eleven parental lines with days to 50% flowering ranging from 49 d (MN 5) to 103 d (ICP 6974) were crossed using a full diallel mating design. A pedigree-based approach was followed to select for early flowering. The selection gain was larger initially (reduction of 7 d) but there was less reduction (2 d) from F3 to F4. Determinate and NDT lines that flowered in 45 to 56 d at ICRISAT-Patancheru reached advanced (F5 and F6) generations. The newly developed lines flowered and matured at a higher latitudes (tested at 30° N vs. 17° N) and altitudes (tested at 1250, 545, and 247 m asl). These lines could be used in new cropping systems (i.e., pigeonpea–wheat [Triticum aestivum L.]) that would allow expanding pigeonpea production to nontraditional planting areas (i.e., wider latitudes and higher altitudes) and could even offer wider planting time flexibility to farmers