http://www.erepo.iihr.ernet.in/handle/123456789/51 Wed, 15 May 2013 11:42:15 GMT 2013-05-15T11:42:15Z http://www.erepo.iihr.ernet.in/handle/123456789/190 Title: Studies on parental synchronization in flowering for hybrid seed production in Onion (Allium cepa L). Authors: K, Padmini; Veere, Gowda; L B, Naik Abstract: An experiment was conducted at Indian Institute of Horticultural Research, Bangalore in Rabi season during the years 2001-2002 and 2002-2003 to study the flowering of CMS (A) and pollinator lines (C) of onion cv. Arka Lalima for effective synchrony in hybrid seed production. Results indicated that days to 100% flowering and days to complete flowering in a plant varied significantly in the parental lines and C line was earlier than A line by 12 days and 25 days respectively. The duration of flowering in a plant was also lesser in C line (23 days) than in A line (29 days). Due to lack of floral synchrony between parental lines, pollen availability is a limiting factor in hybrid seed production of Arka Lalima. Delayed planting of C lines by one week after planting A lines resulted in synchronised flowering of parental lines at peak flowering stage. This also resulted in higher fruit set (80%) and hybrid seed yield (15g/plant) as against planting of A and C lines simultaneously (29.54% and 0.38g respectively). Mon, 01 Jan 2007 00:00:00 GMT http://www.erepo.iihr.ernet.in/handle/123456789/190 2007-01-01T00:00:00Z http://www.erepo.iihr.ernet.in/handle/123456789/188 Title: Effect of pre-soaking treatments and temperature on seed germination of guava (Psidium guajava L.) Authors: K, Bhanu Prakash; H S, Yogeesha; C, Vasugi; M N, Arun; L B, Naik Abstract: The effect of various pre-soaking treatments (soaking in distilled water (DW), GA3 100, 500 and 1000 ppm for 24 and 48 h and HCl (35%) for 3 and 5 minutes) and temperature (constant - 32o C for 24h and alternating temperatures of 32/29 32/25 and 32/20 oC for 6/18h) on promotion of seed germination in various guava accessions (EC147037, EC14039, EC147036 and EC 162904) was tested. Among the pre-soaking treatments soaking in DW followed by GA3 for 48 h was found superior whereas soaking in HCl (35%) for 5 minutes inhibited germination significantly. Alternating temperature of 32/20 oC resulted in maximum (100%) germination when compared to other temperature conditions. The magnitude between upper and lower temperatures in the alternating temperature range also affected seed germinability. When the temperature range was from 32 to 20o C, all accessions demonstrated maximum germination, but when temperatures ranged from only 32 to 29oC, germination of most of the accessions was lower, and closer to that when temperature was a constant 32C. Tue, 01 Jan 2008 00:00:00 GMT http://www.erepo.iihr.ernet.in/handle/123456789/188 2008-01-01T00:00:00Z http://www.erepo.iihr.ernet.in/handle/123456789/187 Title: Physiological and biochemical changes in relation to seed quality in ageing bell pepper (Capsicum annuum L) seeds. Authors: K, Bhanu Prakash; H S, Yogeesha; M N, Arun Abstract: A study was conducted during the year 2006-2008 to identify physiological (per cent germination, germination rate, seedling vigour index, germination index and standard germination) and biochemical changes (membrane injury, malonaldehyde content, total soluble sugars, amylase, peroxidase and dehydrogenase activity) in relation to seed vigour and viability, in fresh and aged bell pepper seeds (Capsicum annum L.). Results revealed an overall decrease in germination, vigour and enzyme activity with increase in ageing duration. Increased membrane injury (1.2-2.05 times) and lipid peroxidation (1.09-1.38 times) coupled with significant reductions in dehydrogenase (34.5 –100%) and amylase activity (42.9-100 %) were noticed in accelerated aged (3-15 days) seeds. Peroxidase activity remained unaltered up to nine Days after Accelerated Ageing (9 DAA) but declined significantly at 12 and 15 DAA. Changes in protein and isozymes profiles in aged seeds compared to fresh seeds further indicated that the loss in seed quality might be due to adverse effect of ageing on proteins. The electrophoretic variations in proteins and enzymes noticed in the present study could be used as criteria in assessing the quality of bell pepper seed lots. Fri, 01 Jan 2010 00:00:00 GMT http://www.erepo.iihr.ernet.in/handle/123456789/187 2010-01-01T00:00:00Z http://www.erepo.iihr.ernet.in/handle/123456789/186 Title: Effect of temperature and chemical pre-treatment on seed germination in papaya (Carica papaya) Authors: H S, Yogeesha; K, Bhanu Prakash; L B, Naik Abstract: Alternate temperature of 20 0C for 16h and 32 0C for 8 h was found optimum for papaya seed germination with 69.5, 92.0 and 61.5 per cent germination in fresh seeds of ‘Surya’, ‘CO2’ and ‘CO7’ as against 0.0, 11.5 and 2.0 per cent respectively, in seeds without any treatment at constant temperature of 25 0C. Among the chemical treatments, only GA3 could improve the germination significantly at 25 0C. GA3 @ 200 ppm was found effective at 25 0C in all cultivars with 85.0, 69.3 and 75.0 per cent germination in ‘Surya’, ‘CO2’ and ‘CO7’, respectively. Sarcotesta had no role in inhibiting seed germination. Drying methods also did not affect seed germination significantly. Soaking papaya seeds in GA3 @ 200-400 ppm for 48 h before sowing would greatly improve the germination and emergence in the nursery. Mon, 01 Jan 2007 00:00:00 GMT http://www.erepo.iihr.ernet.in/handle/123456789/186 2007-01-01T00:00:00Z