7 research outputs found
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No full textNot AvailableAn experiment on effect of defoliation at different spike initiation stages on biomass partitioning
was conducted for two consecutive years during 2005-07 using DCS-9 variety. Treatments consisted
of four defoliation levels (25%, 50%, 75% and 100%) at primary, secondary and tertiary spike initiation
stages on entire plant along with control, with 3 replications in RBD. With increase in percent defoliation
at any stage there was reduction in stem, leaf, capsule dry weight which resulted in significant reduction
in total dry matter. There was compensation in growth only up to 25% defoliation at any stage. Only
primary seed yield was affected with defoliation at primary spike initiation stage, but with secondary
stage defoliation, yield of all order branches was affected. Secondary, tertiary and quarternary seed yield
was affected with defoliation at tertiary stage. Yield of one order decreased with >25% defoliation at
that order and >50% defoliation at next lower or higher order spikes.Not Availabl
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No full textNot AvailableSixty four genotypes were sown in two specially constructed structures at DOR to identify castor germplasm and breeding lines for better water use efficiency (WUE) and root traits. In each structure, 32 lines were sown in two replications with four plants per replication. Observations on various growth parameters, WUE traits, root characters and total dry matter (TDM) were recorded at the time of harvest (90 days after sowing). Among different root characters, root volume and root dry weight showed strong positive correlation (r > 0.80) compared to root length (r = 0.32) with TDM. Leaf area index (LAI) and stem girth also showed strong positive correlation of >0.80 with TDM. Among the 64 lines screened, thirteen lines showed root length >230 cm, root volume of >250 ml, root dry weight of >40g, LAI >3.0 and TDM >350g/plant. These lines include RG 1450, RG 1611, RG 1661, RG 1826, RG 2122, RG 2149, RG 2714, RG 2797, RG 2826, RG 2850, RG 3063, GCH 5 and 48-1.Not Availabl
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No full textcastor root traitsThe present study aimed to estimate the genetic diversity; variability and heritability in 64 castor genotypes
for root, shoot and water use effi ciency (WUE) traits and further identify the suitable genotypes for a drought
resistance breeding programme. Characters like plant height, leaf area index (LAI), stem girth and total dry
matter (TDM) were signifi cantly correlated (>0.70) with root volume and root dry weight. The genotypes were ranked based on the index in ascending order considering fi ve important characters viz; LAI, stem girth, root volume, root dry weight and TDM using principal component analysis and 15 genotypes with high performance in terms of shoot and root characters were selected. These genotypes comprised 48-1, RG 2124, RG 2169, RG 2155, RG 2074, GCH-5, RG1963, RG 2094, DCS-99, RG 2153, DCS-78, RG 27, RG 1618, RG 2147 and RG 1673. High general combining ability (GCV) and heritability (>80%) for plant height, root volume, root dry weight, TDM and LAI indicate suffi cient variability for selection for these characters. Heterosis was high for TDM, root dry weight, volume and LAI. Superior heterobeltiosis was observed for TDM, root volume and root dry weight. The hybrid GCH-5 with its signifi cant heterosis, heterobeltiosis and standard heterosis for key root traits like root volume, root dry weight and TDM is worth exploring under water scarce conditions.Not Availabl
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No full textNot AvailableThe present study aimed to estimate the genetic diversity; variability and heritability in 64 castor genotypes for root, shoot and water use efficiency (WUE) traits and further identify the suitable genotypes for a drought resistance breeding programme. Characters like plant height, leaf area index (LAI), stem girth and total dry matter (TDM) were significantly correlated (>0.70) with root volume and root dry weight. The genotypes were ranked based on the index in ascending order considering five important characters viz; LAI, stem girth, root volume, root dry weight and TDM using principal component analysis and 15 genotypes with high performance in terms of shoot and root characters were selected. These genotypes comprised 48-1, RG 2124, RG 2169, RG 2155, RG 2074, GCH-5, RG1963, RG 2094, DCS-99, RG 2153, DCS-78, RG 27, RG 1618, RG 2147 and RG 1673. High general combining ability (GCV) and heritability (>80%) for plant height, root volume, root dry weight, TDM and LAI indicate sufficient variability for selection for these characters. Heterosis was high for TDM, root dry weight, volume and LAI. Superior heterobeltiosis was observed for TDM, root volume and root dry weight. The hybrid GCH-5 with its significant heterosis, heterobeltiosis and standard heterosis for key root traits like root volume, root dry weight and TDM is worth exploring under water scarce conditions.Not Availabl
