| 000 | 04474nam a2200169 4500 | ||
|---|---|---|---|
| 999 |
_c161892 _d161892 |
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| 082 |
_a630.28 _bIVY/GE |
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| 100 | _aIvy Mary Rajan | ||
| 245 | _aGenetic evaluation of F2 generation for yield and water stress tolerence in upland rice | ||
| 260 |
_aVellayani _bDepartment of Plant Breeding and Genetics, College of Agriculture _c2018 |
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| 300 | _a118p. | ||
| 502 | _aMSc | ||
| 520 | 3 | _aThe present study entitled “Genetic evaluation of F2 generation for yield and water stress tolerance in upland rice” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2016-2018. The objective was to evaluate the pattern of variability in F2 for yield and yield contributing traits under upland and drought situations and to select superior segregants combining drought tolerance and high yield. The study material included four parents and three F2 populations selected from the Ph.D project entitled “Genetic analysis of drought tolerance in rice (Oryza sativa L.)”. The study comprised of two experiments .In experiment- I, the parents and F2 segregants were raised under rainfed upland condition exposed to natural stress. Among the F2 populations, Vaishak x Harsha (T6) recorded the highest mean grain yield plantˉ1 (38.45g – 48.15g) and lowest mean spikelet sterility (7.76%-21.18%). T6 recorded the highest mean values for number of productive tillers plantˉ1 (9 - 16) and leaf area index (mean: 1.67). Vaishak x Vyttila 6 (T5) recorded the highest mean values for number of spikelets panicleˉ1 (149 - 178), harvest index (44.88% – 48.15%) and proline content (mean: 0.29mg g−1). Thottacheera x Harsha (T7) recorded the highest mean values for chlorophyll(mean: 1.78mg g−1) and leaf soluble protein content (mean: 9.36mg g−1). The data obtained was subjected to transgressive segregation analysis and in T5 more than 50 percent positive segregants were observed for number of productive tillers plantˉ1, spikelet sterility, number of spikelets panicleˉ1 and panicle length. T6 recorded high percentage of positive segregants for number of productive tillersˉ1, grain yield plantˉ1, plant height and spikelet sterility. In T7 percentage of positive segregants were the highest for spikelet sterility and number of productive tillers plantˉ1. Dendrogram drawn on the basis of squared Euclidean distances classified the genotypes into four clusters. Cluster I -T1,T5,T6, cluster II- T4, cluster III -T2,T7 and cluster IV-T3. In experiment II, another set of parents and F2 segregants were grown under rainshelter imposing reproductive stage moisture stress. Irrigation was given at 20mm depth once in seven days from panicle initiation stage onwards. Among the F2 segregants, T5 recorded the highest mean values for grain yield plantˉ1 (11.80g – 18.88g), number of spikelets panicleˉ1 (128 - 174), grain weight panicleˉ1 (2.60g – 4.33g ), harvest index (42.44 % - 68.13%) and proline content (mean: 0.57) and the lowest for spikelet sterility (5.50% - 22.27%). T6 recorded the highest mean value for panicle length (19.60cm – 27.50cm). T7 marked the highest mean values for number of productive tillers plantˉ1 (3 – 7), chlorophyll (mean: 1.28mg g−1) and leaf soluble protein content(mean: 8.82mg g−1) and leaf area index (mean: 0.71). In T5, more than 50 percent of positive segregants were recorded for grain weight panicleˉ1, number of filled grains panicleˉ1 and number of spikelets panicleˉ1. T6 recorded higher percentage of positive segregants for straw yield plantˉ1 whereas T7 recorded the highest positive segregants for 1000 grain weight. On the basis of dendrogram drawn the genotypes were grouped into four clusters. Cluster I -T4 and T6, cluster II-T2,T7, cluster III - T3, T5 and cluster IV - T1. Among the F2 segregants, Vaishak x Harsha (T6) performed well under upland condition whereas Vaishak x Vyttila 6 (T5) performed well under stress. The high yielding variety Vaishak released for uplands might have transferred its superior yield characters to the progeny. The transgressive segregants with favourable traits thus obtained can be effectively utilised for selecting superior genotypes combining drought tolerance and high yield. | |
| 650 | _aPlant breeding and Genetics | ||
| 700 | _aLekha Rani,C (Guide) | ||
| 856 | _uhttp://krishikosh.egranth.ac.in/handle/1/5810147339 | ||
| 942 |
_2ddc _cTH |
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