<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.)"^^ . "Chickpea (Cicer arietinum L.), an important cool-season, food legume\r\ncrop, is known to be sensitive to several abiotic stresses: drought, salinity\r\nand heat. The yield losses caused by these stresses are accounted to 6.4\r\nmillion tonnes (t)/ year on global production. To improve any existing\r\ncultivar and harness the genetic regions involved in the tolerance it is\r\nimportant to understand the genetic and physiological mechanisms that\r\nunderlie any tolerance. The objectives of this study were to (i)\r\nunderstanding the effect of either water deficit or salt stress on the\r\nreproductive biology of genotypes know to contrast for either salt or\r\ndrought stress and (ii) construction of genetic map and identification of\r\nQTLs and candidate genes for salinity tolerance in 188 RILs derived from\r\nthe ICCV 2 × JG 11 cross.\r\nIn the water deficit study conducted in two consecutive years, ten\r\ngenotypes with contrasting yields under terminal drought stress in the\r\nfield were exposed to a gradual, but similar, water stress in the\r\nglasshouse. Nine parameters related to yield were recorded in wellwatered\r\nplants (WW) and in water-stressed plants (WS) when the level of\r\ndeficit was mild (phase I), and when the stress was severe (phase II). The\r\nWS treatment reduced seed yield, seed and pod number, but not flower +\r\npod + seed abortion percentage or 100-seed weight. The controlled\r\ndrought imposition in glass house conditions revealed genotypic\r\ndifferences inthe sensitivity of the reproductive process to drought. The\r\nseed yield differences in chickpea were largely related to the capacity to\r\nproduce a large number of flowers and to set seeds, especially when the\r\ndegree of water deficit was mild.\r\nIn the salinity experiments, fourteen genotypes of chickpea (Cicer\r\narietinum L.) were used to study yield parameters, and eight genotypes\r\nwere selected for ion analysis after being grown in soil treated with 0 mM\r\nand 80 mM NaCl, to assess any possible relationship between salt ion\r\naccumulation in different plant tissues and yield reduction. Salinity\r\ndelayed flowering and the delay was greater in sensitive than tolerant\r\ngenotypes under salt stress. Filled pod and seed numbers, but not seed\r\nsize, were associated with seed yield in saline conditions, suggesting that\r\nsalinity impaired reproductive success more in sensitive than tolerant\r\nlines. The delay in flowering was associated with higher concentrations of\r\nNa+ in the laminae of fully expanded young leaves (R2=0.61) and old\r\ngreen leaves (R2=0.51). Na+ accumulation in leaves was associated with\r\ndelayed flowering that in turn could have played a role of the lower\r\nreproductive success in the sensitive lines.\r\nIn QTL mapping for salinity tolerance, yield and components were\r\nassessed in 188 recombinant inbred lines (RILs) derived from cross ICCV\r\n2 × JG 11, in soil treated with either 0 mM NaCl (control) or 80 mM NaCl\r\n(salinity) over two consecutive years. Salinity significantly (P<0.05)\r\naffected almost all traits across years. The mean yield reduction under\r\nsalinity compared to control was around 40% across years. A genetic\r\nmap was constructed using 56 (SSR, SNP) polymorphic markers. The\r\nQTL analysis revealed two key genomic regions on CaLG05 (28.6 cM) and\r\non CaLG07 (19.4 cM) that harboured QTLs for salinity tolerance\r\nassociated traits. Two major QTLs for higher yield in the salinity\r\ntreatment (explaining 12 and 17% of the phenotyping variation) wereidentified within the two key genomic regions. Comparison with already\r\npublished chickpea genetic maps showed that these regions conferred\r\nsalinity tolerance across two other populations and the markers can be\r\ndeployed for enhancing salinity tolerance in chickpea. Based on gene\r\nontology annotation 48 putative candidate genes responsive to salinity\r\nstress were found. Most of them were believed to be involved in achieving\r\nosmoregulation under stress conditions.\r\nIn the relative humidity stress study, five genotypes that contrasting for\r\nyield under heat stress were studied. The plants were grown in three\r\ndifferent vapor pressure deficit conditions (2.5, 3.0, 3.4 kPa) where the\r\ntemperature was maintained constant (30°C) and the RH varied as 40,\r\n30, 20% respectively. Genotypic variation found for almost all traits\r\nacross treatments. The traits seed number and seed weight differentiated\r\ntolerant and sensitive group significantly at VPD conditions 2.5 and 3.0\r\nbut not in 3.4 kPa. Seed size was unaffected under 2.5 and 3.0 kPa VPD\r\nregimes but did get reduced upto 45% under 3.4 kPa treatment\r\ncompared to 2.5 kPa treatment. The lowest RH treatment, even under\r\nfully well-watered condition, as any other abiotic stress reduced yield.\r\nThus, it is important to consider the effect of low RH and the\r\nmechanisms behindits tolerance and sensitivity in future heat tolerance\r\nstudies. The pollen viability or pollen in vivo germination was unaffected\r\nin this study.\r\nAll the four studies have revealed that certain parameters can be used for\r\nachieving water deficit, salinity and relative humidity stress tolerance in\r\nfuture chickpea improvement programs."^^ . "2015" . . . . "Bharathidasan University,Tiruchirappalli, Tamil Nadu"^^ . . . "Department of Plant Science Center of Excellence in Life Sciences, Bharathidasan University,Tiruchirappalli, Tamil Nadu"^^ . . . . . . . . "R"^^ . "Pushpavalli"^^ . "R Pushpavalli"^^ . . . . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.) (PDF)"^^ . . . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.) (Other)"^^ . . . . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.) (Other)"^^ . . . . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.) (Other)"^^ . . . . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.) (Other)"^^ . . . . . . "Physiological and genetic deciphering of water,\r\nsalinity and relative humidity stress in chickpea\r\n(Cicer arietinum L.) (Other)"^^ . . . . . "HTML Summary of #9117 \n\nPhysiological and genetic deciphering of water, \nsalinity and relative humidity stress in chickpea \n(Cicer arietinum L.)\n\n" . "text/html" . . . "Chickpea"@en . .