Collection, evaluation, characterization, maintenance and utilization of castor germplasm 2015

Abstract

Augmentation: A castor germplasm exploration was conducted in Chhindwara region of Madhya Pradesh, and Warud region of Amaravati District, Maharashtra in collaboration with Zonal Agricultural Research Station, Chhindwara and collected 32 accessions of castor possessing many productive spikes, partially female raceme types, high yield (around 5-6 kg/plant), bold and non spiny capsules, white, red, dark brown and white seeded types, long secondary spikes, Co-1 type with white seeds and small leaves, and compact and long spike (70-80 cm) etc.Characterization and evaluation of fresh collections: One hundred and eighty new accessions collected from Rajasthan and S.K. Nagar during 2013-14 have been characterized for 23 descriptors and evaluated for 19 quantitative traits at IIOR, Hyderabad. Great diversity was observed among the fresh accessions with respect to morphological and quantitative traits. Twenty two accessions having desirable characters have been selected. Three accessions (RG-3859, RG-3946, RG-3963) exhibited low node number (7-9) while the best check, GCH-7 had 15 nodes up to primary spike. Higher 100- seed weight (50-53.2 g) than GCH-7 (31 g) was recorded in three accessions viz., RG-3832 (53.2g), RG-3839 (52.6g), and RG-3831 (50g). Seven accessions recorded higher seed yield than GCH-7 (431 g/net plot) at 150 days after planting (649-1256 g/net plot) and 180 DAP (612-998 g/net plot; GCH-7: 429 g/net plot); four have recorded higher seed yield (1821-2974 g/net plot) than GCH-7 (1530 g/net plot) at 210 DAP. RG-3859 having low node number (7) gave higher seed yield at 120 DAP (1256 g/ net plot) and 180 DAP (998 g/net plot). Higher total seed yield than GCH-7 (3074 g/net plot) was realized from four accessions namely, RG-3850 (3589 g/net plot), RG-3880 (3453 g/net plot), RG-3938 (3413 g/net plot), RG-3860 (3233 g/net plot). RG-3850 recorded the highest total yield (3589 g/net plot).

Diversity assessment of fresh collections: The 180 fresh accessions from Rajasthan and S.K. Nagar have been grouped into four diverse groups by Wards’ minimum variance method of cluster analysis.Yield evaluation, diversity analysis and confirmation of trait-specificity of promising germplasm selections Agronomic and yield and yield traits: The germplasm selection, RG-43 (IC-0584671), which is wilt and leafhopper resistant, has confirmed its early maturity (DF: 53 days; check GCH-7: 67 days) in a multilocation evaluation trial. RG-3798 has exhibited long effective length of primary spike (68 cm; GCH-7: 60 cm) trait at multilocations confirming its ability to produce long productive primary spike under varying environments. High yielding ability of four selections, RG-3491 (2740 g total yield/net plot; GCH-7: 2580 g total yield/net plot), RG-3160 (2626 g/ net plot), RG-3798 (2682 g/ net plot) and RG-3799 (2406 g/ net plot), have been confirmed in a replicated multilocation evaluation trial in rainfed and irrigated situations. The high yielding ability of three germplasm selections viz., RG-1647 (1827 g/net plot), RG-2375 (1968 g/net plot) and RG-3767 (2272 g/net plot) has been confirmed in the second year at IIOR, Hyderabad in a preliminary evaluation trial while GCH-7 recorded yield of 2121 g/net plot (CV:20%;CD0.05: 142) .

High ricinoleic acid: High ricinoleic acid content ranging from 90 to 92% has been confirmed in 14 germplasm selections in the second consecutive year in a multilocation evaluation trial conducted at four locations. The selection, RG-226 have possessed the highest ricinoelic acid (92%) content whilst the checks, GCH-7, DCH-519, 48-1, DCS-106, DCS-9 and GC-3 had 86-88% ricinoleic acid content. Among the 14 high ricinoleic acid selections, 2 to 22% higher seed yields than the best check, GCH-7 (1979 g/net plot) have been realized from RG-3467 (2413 g/net plot), RG-311 (2231g/net plot), RG-370 (2070 g/net plot) and RG-63 (2013 g/net plot) in a replicated multilocation evaluation trial.

Drought resistant accessions: Higher seed yields than GCH-7 (4040 g/net plot; CV: 16%, CD0.05: 137) were recorded in three putative drought tolerant accessions viz., RG-707 (4102 g/net plot), RG-27 (4141 g/net plot) and RG-1117 (4937 g/net plot) in a replicated yield evaluation trial at IIOR, Hyderabad. The Principal Component Analysis of 30 putative drought tolerant accessions has revealed wide diversity among the accessions based on 18 agro-morphological traits (Fig.3). Wilt resistant selections: Among the 15 wilt resistant selections from germplasm (<20% wilt incidence), two have yielded (3264-3301 g/net plot) at par with GCH-7 (3315 g/net plot; CV: 20%, CD: 771) in a replicated evaluation trial at IIOR, Hyderabad. Leafhopper resistant selections: Two leafhopper resistant selections viz., RG-2562 and RG-2661 have yielded (3045-3335 g/net plot) at par with the best check, DCH 519 (3015 g/net plot; CV: 16, CD0.05: 845) in a replicated evaluation trial at IIOR, Hyderabad. The 14 leafhopper resistant selections, which confirmed resistance in the second consecutive year at multilocation under artificial epiphytotic conditions, have been grouped into seven distinct groups by Wards’ minimum variance method of cluster analysis using 18 agro-morphological traits.

Development of heterotic groups:Thirty five accessions were found to be heterotic for short plant height, low node number, early maturity, long productive primary spike, high 100-seed weight and seed yield when crossed to non-TSP-10 R-based pistillate lines which were developed from germplasm accessions.

Prebreeding for inbred lines development Plant-progeny-wise selections and sib-crossings were made among 15 trait specific selections from germplasm identified for high ricinoleic (90-92%), wilt resistance (<20% DI), leafhooper resistance (0 hopper burn), leaf miner resistance, extra-early maturity in order to develop inbreds possessing these traits.

Multiplication, documentation, supply and utilization of germplasm Multiplied 329 accessions and passport information, morphological descriptors and data on quantitative traits of 180 fresh accessions were documented. Supplied 570 accessions to various AICRP (Castor) centres for multilocation yield evaluation and screening against diseases and insect pests besides 517 accessions were for research purpose to various castor researchers in the country. Twenty one trait-specific accessions (Table 1) have been utilized in fresh crossing programmes by castor breeders at Hiriyur, IIOR, Hyderabad, Junagadh, Kanpur, Navasri and Palem centres during 2014-15.

Germplasm Registration:The castor germplasm selection, RG-2822 (IC0346626; INGR1 4028), proposed for resistance to Macrophomina root rot, was approved for registration by Plant Germplasm Registration Committee (PGRC) in its XXIXth meeting held on May 5th, 2014.