MOLECULAR BIOLOGY AND PHYSIOLOGY Temperature Induction Response as a Screening Technique for Selecting High Temperature-Tolerant Cotton Lines

ABSTRACT Cotton is cultivated in a wide range of environments from tropical to subtropical regions. In India, approximately 70%of the total land area covered by cotton is grown under rain-fed conditions where cotton frequently experiences drought stress along with other stresses, e.g.,high temperature and high salinity. There is a need to develop a technique to screen a large number of genotypes for high temperature tolerance. In this study, a screening protocol was developed based on the principle of "acquired tolerance" in which exposure of seedlings to a sublethal level of specific stress is used to induce tolerance to a subsequent lethal level of stress. After adapting this temperature induction response (TIR) technique to cotton, several species and varieties were screened for thermotolerance. Among the tested entries, Old World cotton species showed better thermotolerance than New World cotton species. Among 36 diverse Gossypium hirsutum germplasm lines, significant variation in acquired thermotolerance was seen. Thermotolerant genotype G. hirsutum (H-28), identified by the TIR technique, demonstrated increased cell viability and protein synthesis capacity during alleviation from high temperature stress. Results suggested that TIR is a robust and powerful technique and can be used to screen breeding lines or germplasms to identify thermotolerant lines

Protein-quality evaluation of complementary foods in Indian children

Background: The types of food in complementary feeding of infants and young children are important for growth and development. Food protein quality, as measured by the Digestible Indispensable Amino Acid Score (DIAAS), requires the determination of true ileal digestibility of indispensable amino acids (IAAs) in children. Objectives: First, the aim of this study was to measure the true ileal IAA digestibility of 4 (rice, finger millet, mung bean, and hen egg) commonly consumed complementary foods in children aged <2 y using the dual-isotope tracer method. Second, we calculated the DIAAS of complementary feeding diets and their relation to stunting in a representative Indian rural population. Design: Rice, finger millet, and mung bean were intrinsically labeled with deuterium oxide (2H2O), whereas egg was labeled through oral dosing of hens with a uniformly 2H-labeled amino acid mixture. True ileal IAA digestibility was determined by the dual-isotope tracer technique. The DIAAS of complementary food protein was calculated in children aged 1–3 y from a nationally representative survey to evaluate its relation with stunting. Results: True ileal IAA digestibility was lowest in mung bean (65.2% ± 7.1%), followed by finger millet (68.4 %± 5.3%) and rice (78.5% ± 3.5%), and was highest for egg (87.4% ± 4.0%). There was a significant inverse correlation of complementary food DIAAS with stunting in survey data (r = −0.66, P = 0.044). The addition of egg or milk to nationally representative complementary diets theoretically improved the DIAAS from 80 to 100. Conclusions: The true ileal IAA digestibility of 4 foods commonly consumed in complementary diets showed that the DIAAS was associated with stunting and reinforces the importance of including animal source food (ASF) in diets to improve growth. This trial was registered at http://ctri.nic.in/clinicaltrials/login.php as CTRI/2017/02/007921

Wireless Sensor Networking for Rain-fed Farming Decision Support

Wireless sensor networks (WSNs) can be a valuable decision- support tool for farmers. This motivated our deployment of a WSN system to support rain-fed agriculture in India. We defined promising use cases and resolved technical challenges throughout a two-year deployment of our COMMON- Sense Net system, which provided farmers with environment data. However, the direct use of this technology in the field did not foster the expected participation of the population. This made it difficult to develop the intended decision-support system. Based on this experience, we take the following position in this paper: currently, the deployment of WSN technology in developing regions is more likely to be effective if it targets scientists and technical personnel as users, rather than the farmers themselves. We base this claim on the lessons learned from the COMMON-Sense system deployment and the results of an extensive user experiment with agriculture scientists, which we describe in this paper

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Not AvailableWild Arachis genotypes were analysed for chlorophyll a fluorescence, carbon isotope discrimination (ΔC), specific leaf area (SLA), and SPAD readings. Associations between different traits, i.e., SLA and SPAD readings (r = –0.76), SLA and ΔC (r = 0.42), and ΔC and SPAD readings (r = 0.30) were established. The ratio of maximal quantum yield of PSII photochemistry (Fv/Fm) showed a wider variability under water deficit (WD) than that after irrigation (IR). Genotypes were grouped according to the Fv/Fm ratio as: efficient, values between 0.80 and 0.85; moderately efficient, the values from 0.79 to 0.75; inefficient, the values <0.74. Selected genotypes were evaluated also for their green fodder yield; the efficient genotypes ranged between 3.0 and 3.8, the moderately efficient were 2.6 and 2.7, the inefficient genotypes were of 2.3 and 2.5 t ha–1 per year in 2008 and 2009, respectively. Leaf water-relation traits studied in WD and IR showed that the efficient genotypes were superior in maintenance of leaf water-relation traits, especially, under WD. Potential genotypes identified in this study may enhance biomass productivity in the semiarid tropic regionsNot Availabl

Relationship between carbon isotope discrimination, ash content and grain yield in wheat in the Peninsular Zone of India

International audienceCarbon isotope discrimination (Δ) and ash content (ma) have been proposed as indirect selection criteria for grain yield in wheat. The associations between Δ, ma and grain yield were found, however, to depend highly on the environmental conditions, the organ sampled and the time of sampling. In this study, carried out in the warm conditions of the Peninsular Zone of India, the relationship between Δ, ma and yield was studied in 30 bread and durum wheat cultivars under residual soil moisture stress (RSMS), post-anthesis water stress (PAWS) and well-watered (WW) conditions. Both Δ and ma were analysed in young seedlings (four-leaf stage), leaves at anthesis and grain at maturity. Ash content was also evaluated in leaves at booting stage and maturity. Grain Δ was lower under PAWS and RSMS than under WW, while seedling and leaf Δ did not significantly differ among water regimes. Grain yield was positively correlated to grain Δ under PAWS and negatively correlated to grain ma under RSMS. A significant positive correlation was noted under RSMS and WW treatments between maLm and grain yield. Ash content in leaf at maturity consequently appears to be a useful indirect selection criterion in environments where Δ does not show any correlation with yield. The results highlight the potential of Δ and ma as indirect selection criteria for wheat yield in the conditions of the Peninsular Zone of Indi

G4008.12: Linking genetic diversity with phenotype for drought tolerance traits through molecular and physiological characterization of a diverse reference collection of chickpea

World wide, terminal drought is a key constraint to chickpea productivity. Incorporation of morphological and physiological traits that are strongly associated with drought tolerance into well adapted genetic backgrounds is expected to improve the yield stability. The accessions of chickpea reference collection were chosen to be phenotyped for carbon isotope discrimination (Δ13C), the best opted estimate of transpiration efficiency (TE). These accessions were also phenotyped for specific leaf area (SLA) and SPAD chlorophyll meter readings that are considered as two other proxies for TE. The collaborating centres, University of Agricultural Sciences, Bangalore and ICRISAT, Patancheru, were chosen on the basis of diversity in short duration growing environment and Isotope-ratio mass spectrometry capability of University of Agricultural Sciences, Bangalore and JIRCAS, Japan. The field experiments conducted both in 2008-09 and 2009-10 at ICRISAT, Patancheru, had shown that the accessions of the reference collection ranged from 35 to 66 days in 50% flowering and 79 to 115 days to maturity and the optimum irrigation application extended the mean maturity time by 15 days. Shoot biomass production ranged from 2800 to 5500 kg ha-1 and the grain yields ranged from 1400 to 2800 kg ha-1 under terminal drought that was found enhanced with optimum irrigation to 3600 to 8900 in shoot biomass and 700- 2300 in seed yield. Large variations in Δ13C values were observed that ranged from -0.25.5 to -0.28.0 in 2008-09 and -24.2 to -27.2 in 2009-10 under drought while the range was narrow under optimally irrigated conditions. Δ13C variation was significantly associated with per day grain productivity and the explained 7% of the variation in 2008-09 while 25% in 2009-10. Also the phenology and the yield components were also largely and significantly associated with Δ13C. SPAD or SLA, the surrogates of TE, were not significantly associated with Δ13C but SLA and SPAD were significantly and negatively associated with each other. The trials at UAS, Bangalore did not succeed in both the years due a late sowing in 2008-09 and a poor germination in 2009-10. A genotyping using DArT markers resulted in identifying 1157 polymorphic markers on the reference collection. The marker trait association lead to the identification two DArT markers that were closely associated with the Δ13C trait under terminal drought. The results and general experience was shared with the future NARS users and collaborators in Tropical Legumes I and II from Africa and Asia in a training cum capacity building workshop conducted between 25-29 May 2010 at JIRCAS, Japan and Hokkaido University, Sapporo, Japan. Parellel findings in another study had revealed that the QTL for Δ13C also colocalized the same genomic region where large number of QTLs for various other drought tolerance traits, related to root traits, yield and HI. This offers an advantage for the ongoing molecular breeding efforts in chickpea drought tolerance where an introgression of this genomic region into elite cultivars is expected to improve all the desirable traits in one attempt. Also the root QTL introgressed progenies (BC3F3) developed in a parallel study can be an ideal material to look for these markers in the selection process. The results are being written up as journal articles and the data will be uploaded into the GCP central registry after Sep 2011

Genetic dissection of drought tolerance in chickpea (Cicer arietinum L.)

Chickpea (Cicer arietinum L.) is the second most important grain legume cultivated by resource poor farmers in the arid and semi-arid regions of the world. Drought is one of the major constraints leading up to 50 % production losses in chickpea. In order to dissect the complex nature of drought tolerance and to use genomics tools for enhancing yield of chickpea under drought conditions, two mapping populations—ICCRIL03 (ICC 4958 × ICC 1882) and ICCRIL04 (ICC 283 × ICC 8261) segregating for drought tolerance-related root traits were phenotyped for a total of 20 drought component traits in 1–7 seasons at 1–5 locations in India. Individual genetic maps comprising 241 loci and 168 loci for ICCRIL03 and ICCRIL04, respectively, and a consensus genetic map comprising 352 loci were constructed (http://cmap.icrisat.ac.in/cmap/sm/cp/varshney/). Analysis of extensive genotypic and precise phenotypic data revealed 45 robust main-effect QTLs (M-QTLs) explaining up to 58.20 % phenotypic variation and 973 epistatic QTLs (E-QTLs) explaining up to 92.19 % phenotypic variation for several target traits. Nine QTL clusters containing QTLs for several drought tolerance traits have been identified that can be targeted for molecular breeding. Among these clusters, one cluster harboring 48 % robust M-QTLs for 12 traits and explaining about 58.20 % phenotypic variation present on CaLG04 has been referred as “QTL-hotspot”. This genomic region contains seven SSR markers (ICCM0249, NCPGR127, TAA170, NCPGR21, TR11, GA24 and STMS11). Introgression of this region into elite cultivars is expected to enhance drought tolerance in chickpea

Amino acid digestibility of extruded chickpea and yellow pea protein is high and comparable in moderately stunted South Indian children with use of a dual stable isotope tracer method

Background: Legumes are an excellent plant source of the limiting indispensable amino acid (IAA) lysine in vegetarian, cereal-based diets. However, their digestibility is poor largely because of their antiprotease content. Extrusion can enhance digestibility by inactivating trypsin inhibitors and thus potentially improve the protein quality of legumes. Objective: We measured the digestibility of extruded chickpea and yellow pea protein with use of a dual stable isotope method in moderately stunted South Indian primary school children. Methods: Twenty-eight moderately stunted children (height-for-age z scores &lt;-2.0 SD and &gt;-3.0 SD) aged 6-11 y from low to middle socioeconomic status were randomly assigned to receive a test protein (extruded intrinsically [2H]-labeled chickpea or yellow pea) along with a standard of U-[13C]-spirulina protein to measure amino acid (AA) digestibility with use of a dual stable isotope method. Individual AA digestibility in the test protein was calculated by the ratios of AA enrichments in the test protein to the standard protein in the food and their appearance in blood plasma collected at 6 and 6.5 h during the experiment, representing a plateau state. Results: The mean AA digestibility of extruded chickpea and yellow pea protein in moderately stunted children (HAZ; -2.86 to -1.2) was high and similar in both extruded test proteins (89.0% and 88.0%, respectively, P = 0.83). However, lysine and proline digestibilities were higher in extruded chickpea than yellow pea (79.2% compared with 76.5% and 75.0% compared with 72.0%, respectively, P &lt; 0.02). Conclusion: Extruded chickpea and yellow pea protein had good IAA digestibility in moderately stunted children, which was 20% higher than an earlier report of their digestibility when pressure-cooked, measured by the same method in adults. Higher digestibility of lysine and proline highlights better retention of these AA in chickpea during extrusion-based processing. Extrusion might be useful for developing high-quality protein foods from legumes. This trial was registered at www.ctri.nic.in as CTRI/2018/03/012439