http://www.erepo.iihr.ernet.in/handle/123456789/40 2013-05-16T13:00:41Z http://www.erepo.iihr.ernet.in/handle/123456789/221 Title: Genetics of rate limiting disease reaction to Alternaria solani in tomato. Authors: E S, Rao; A D, Munshi; P, Sinha; Rajkumar Abstract: A study was conducted to understand the genetics of rate limiting disease reaction to Alternaria solani in tomato. The results from ÷2 analysis and Castle Wright estimation revealed that resistance is an oligogenic character controlled by two to few genes. In general, the results for predominant gene effects reveal that both additive and non-additive effects are involved in the inheritance of early blight resistance. The results for predominant gene effects obtained for various crosses studied are discussed along with their implications for improvement of this trait. 2008-01-01T00:00:00Z http://www.erepo.iihr.ernet.in/handle/123456789/220 Title: Identification of sources of resistance to alternaria leaf spot (Alternaria brassicicola), black rot (Xanthomonas campestris) and downy mildew (Peronospora parasitica) in cauliflower (Brassica oleraceae). Authors: B, Varalakshmi; Girija, Ganeshan; C, Gopalakrishnan; A, Pushpalatha; B S, Chethana Abstract: Forty five cauliflower germplasm and advanced breeding lines belonging to early group were screened during 2005-2007 against alternaria leaf spot, black rot and downy mildew diseases. Based on the two years data, none of the cauliflower germplasm or advanced breeding lines was found resistant to the three diseases tested. However, ‘IIHR-260-1’, ‘IIHR-265’, ‘IIHR-302’ and ‘IIHR- 305-1’ were found resistant against downy mildew. Four lines viz., ‘IIHR-73-3-20’, ‘IIHR-250-4-4-16-27’, ‘IIHR-264-3’, ‘IIHR-392’ against alternaria leaf spot and two lines viz., ‘IIHR-73-56’ and ‘IIHR-250-4-1-11-28’ against black rot were found to be moderately resistant. 2009-01-01T00:00:00Z http://www.erepo.iihr.ernet.in/handle/123456789/219 Title: Heterosis and Combining Ability for Yield and its Components in Early Cauliflower Authors: B, Varalakshmi Abstract: Line × Tester analysis involving four lines and five testers was carried out in early cauliflower Brassica oleraceae var. botrytis. The results indicated the predominance of non-additive gene action for days taken for 50% curd initiation, days taken for 50% curd maturity, leaf number, leaf weight, stalk weight, curd size and curd weight. Significant heterosis of 33.9% over standard check, NS-60 for curd weight was expressed by the cross IIHR Sel-5 × IIHR 73-24. The best general combiners were IIHR-Sel-5 and IIHR 223-1 among the lines, and IIHR-73-24 and Arka Kanti-15 among the testers. Best specific combining ability effects for curd weight and curd size were recorded by the crosses IIHR Sel-5 × IIHR 73-24 and IIHR 223-1 × IIHR-302. 2009-01-01T00:00:00Z http://www.erepo.iihr.ernet.in/handle/123456789/218 Title: Development And Evaluation Of Triploid Seedless Watermelon In India. Authors: M, Pitchaimuthu; O P, Dutta; V S R, Krishna Prasad; K R M, Swamy Abstract: Watermelon [Citrullus lanatus (Thumb) Mansf] belonging to family Cucurbitaceae is a diploid (2n=22). The matured fruits of popularly grown regular varieties contain numerous seeds, which are discarded while consuming fruits. Seedless watermelons are commercially advantageous as they either lack seeds or contain small soft rudimentary seeds. The first seedless watermelon was developed by Kihara (1947) in Japan by crossing colchicines induced tetraploids (3n=3x=33) and (2n=22) cultivars. The resultant triploid seeds produced seedless watermelons. In India, watermelon is a cultivated in 20,000 ha, production is 2.55 lakh tones and the productivity is 12.75 mt/ha. Work on induction of polyploidy in watermelon was initiated by Chopra and Swaminathan in 1959. Later Seshadri et al., in 1972 developed the first triploid seedless watermelon “Pusa Bedana’’. This variety had few limitations like poor seed germination, slow maturity and poor triploid seed recovery when their parents a tetraploid and diploid were crossed. Since, there is great demand for triploid seedless watermelon in India, work in this direction was initiated at Indian Institute of Horticultural Research (IIHR) Bangalore, in 1993. cv. Arka Manik (Popular and triple diseases viz., PM,DM and anthracnose resistant variety) the seedlings or seeds were treated with colchicines using different concentrations. Tetraploids to the tune of 30 % were induced with application of 0.3 % aqueous colchicine solution to watermelon seedlings at cotyledon stage for a period of seven consecutive days under shade. However, 19.25 % of the plants only could be induced when 0.3 % colchicines were applied with lanoline paste to the seedlings at cotyledon stage for a period of twelve days (applied twice in a week). The percentage of induced tetraploids was increased to 80 % in a combination involving pretreatment of seeds with Nitsch medium followed by colchicine at 0.9 % colchicine + 4 % Poly Ethylene Glycol (PEG) treatment for 4 days using Nitsch medium and subsequent germination at 32 oC. Forty eight per cent of tertaploid seedlings developed good root system when these were allowed to grow in Nitsch medium supplement with 3 mg each of NAA and Kinetin and 600 ppm Gentamycin. The characteristic gigantism was observed in majority of morphological characters in tetraploid and triploid watermelon plants. During 2005-2008, four triploid seedless watermelon namely, WT-1202 (3x), VAR-TRI-X-PLR (3x), WMX-313 (3x) developed by Syngenta Seeds Pvt. Ltd. and IIHR-TWN-1 (3x) developed by IIHR were evaluated along with two diploid pollinators namely Augusta and Arka Manik for seed germination. Three years data indicated that mean seed germination percent was maximum (83.83 %) in IIHR-TWN-1 followed by WMX-313 with 82.42 %. IIHR-TWN-1 was found promising in terms of high yield and high T.S.S in both open field 10.76 kg/plot area of 9m2 (11.95 t / ha) and T.S.S of 12.23 o brix) and poly house 33.22 kg/ plot area of 6.25 m2 (53.15 t / ha) and T.S.S of 15.5 o Brix) and significantly superior over other triploids over three years. IIHR-TWN-1, fruits are round, light green with dark green stripes. Average fruit weight 4.5 kg with crimson red flesh, crisp texture and superior taste. It has rind thickness of 1.92 cm, which will be useful for long distance transport and longer shelf life. 2010-01-01T00:00:00Z