Journal of Horticultural Sciences

H. S. Yogeesha ¹, B. L. Kashinath ¹, K. Bhanuprakash ¹, L. B. Naik ¹

Affiliations
1 Section of Seed Science and Technology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore-560089, IN

Abstract

A study was conducted to assess the efficiency of specific gravity separator in removing partially filled/chaffy seeds of okra during 2007 and 2008. Bulk seed, after extraction, was first subjected to an air screen cleaner with three screens. Then, the good seed fraction obtained was subjected to specific gravity separation. Three fractions were obtained, viz., heavy, medium and light and they were assessed for quality, along with ungraded seed. Test weight, germination percentage, first count, seedling vigour indices I&II and field emergence were significantly higher in the heavy seed fraction than in ungraded seed. Black seed content in heavy seed fraction was significantly low, thereby improving seed quality. Rejection percentage in terms of light and medium seed fractions put together was 3.5% and 12% in 2007 and 2008, respectively. By removal of these fractions, percentage of field emergence improved from 63% to 82% in 2007, and 62.8 to 76.4% in 2008, respectively.

Keywords

Okra, Specific Gravity Separation, Seed Quality, Black Seed.

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K. Bhanuprakash ¹, H. S. Yogeesha ¹, L. B. Naik ¹, M. N. Arun ¹

Affiliations
1 Section of Seed Science and Technology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore-560 089, IN

Abstract

Rapid loss in viability of onion seeds during seed storage is a major problem. Not much information concerning the physiological and biochemical changes is available. In the present investigations, seeds were aged artificially by exposure to 45°C+75% RH for a period of fifteen days. Samples were collected at three day intervals and physiological and biochemical changes in the aged seeds were compared to those in fresh seeds. Results revealed that ageing affected seed viability and vigour significantly and this effect was more pronounced with increase in duration of exposure to artificial ageing. Marked reduction in germination to an extent of 4,16 and 75% was noticed in three, six and nine day artificially aged (DAA) seeds, respectively, when compared to fresh seeds. Further increase in ageing duration to twelve and fifteen days resulted in total loss of germination. Increase in ageing duration decreased a amylase and dehydrogenase activities but increased peroxidase activity up to nine days of ageing. Lipid peroxidation increased consistently with increase in duration of ageing. At 15 DAA, 26.2% increase in malondialdehyde content over the control was observed. SDS PAGE protein profile and esterase zymograms of aged seeds showed alteration in banding pattern when compared to that of fresh seeds.

Keywords

Onion, Accelerated Ageing, Protein Profiles, Enzymes.

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K. Padmini ¹, R. Veere Gowda ¹, L. B. Naik ¹

Affiliations
1 Section of Seed Science and Technology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore-560 089, IN

Abstract

An experiment was conducted at the Indian Institute of Horticultural Research, Bangalore, in Rabi season during 2001-2002 and 2002-2003 to study the flowering of Cytoplasmic Male Sterile Lines CMS (A) and pollinator lines (C) of onion cv. Arka Lalima for working out 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 found to be earlier than A line by 12 days and 25 days, respectively. The duration of flowering in a plant was also less in C line (23 days) than in A line (29 days). Due to lack of floral synchrony between parental lines, pollen availability becomes a limiting factor in hybrid seed production in cv. Arka Lalima. Delay in planting of C lines by a 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).

Keywords

Cytoplasmic Male Sterility, Flowering, Hybrid Seed Production, Onion, Synchronization.

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K. Padmini ¹, L. B. Naik ¹

Affiliations
1 Section of Seed Science and Technology, Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bangalore-560 089, IN

Abstract

Studies were conducted during 2002-2005 (Rabi season) to evaluate the extent of genetic contamination in round fruited ridge gourd (recessive) vehen grown for seed production under open field conditions. The round fruited ridge gourd was sown at 200 m, 400 m, 600 m and 800 m distance from Arlia Sumeet (long fruited) which acted as the local marker (dominant). The highest percentage of genetic contamination was recorded at a distance of 200 m from the contaminator (Arka Sumeet) (28.62% and 88.1%, respectively, in the years 2003 and 2005). It was also observed that there was a gradual reduction in contamination level with increasing distance from 28.62 to 17.44% at 600 m distance in 2003 and 88.11% at 800 m to 74.23% in 2005. The lowest percentage of contamination was recorded at the highest isolation distance (at 600 m, 17.44% in 2003 and at 800 m, 74.24% in 2005), although it is not within the prescribed maximum permissible limit of genetic contamination (1 and 2% for foundation and certified seed respectively). In the present study, in all the isolation distances studied, the level of contamination is well above the permissible minimum seed certification standards (99 and 98 % genetic purity for Foundation and Certified seed respectively). Hence, any reduction in the isolation distance from the prescribed (800 m) isolation would drastically affect the genetic purity of ridge gourd for seed production under open field conditions.

Keywords

Cucurbits, Genetic Purity, Isolation, Ridge Gourd, Seed Production.

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