Journal of Horticultural Sciences

H. S. Yogeesha ¹, S. Ganeshan ¹, K. S. Shivashankara ¹, D. L. Shetty ¹, C. Anil Kumar ²

Affiliations
1 ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru – 560 089, Karnataka, IN
2 TBGRI, Palode, Thiruvananthapuram, Kerala, IN

Abstract

A study was under taken on fruit and seed morphology, seed drying, seed germination and storage behavior in Baccaurea courtallensis, as, this plant is propagated mainly through seeds. Its fruit is a berry consisting of an outer, semi-hard but fleshy rind 2-3 mm thick. The cavity inside the rind is normally occupied by a single, arillate seed, but, two seeds are also seen occasionally. Fresh rind was found to be rich in antioxidants, with 237mg total phenols and 93mg flavonoids per 100 gram fresh weight, but was poor in Vitamin C. A thick, fleshy endosperm is surrounded by the inner seed-coat. The endosperm surrounds the embryo consisting of two papery-thin cotyledons and a minute embryonic axis. Germination was highest (96.7%) when seeds were sown immediately after extraction, with moisture content of about 50%. Reduction in moisture to below 34% showed a drastic decrease in germination. Dried seeds took longer to germinate than did the fresh ones. Seeds with 21% moisture recorded about 60% germination whereas, seeds with 10.2% or 8% moisture failed to germinate, indicating a recalcitrant seed. Temperature in the range of 25-30°C was found to be optimum. Of the two media tested for raising the seedlings, cocopeat medium was superior as, it induced faster growth of the seedlings. Seedling ischolar_main and shoot were considerably longer, with higher seedling survival rate in cocopeat than in the soil-mix medium. Seedling establishment was poor when planted out of their natural habitat.

Keywords

Baccaurea courtallensis, Seed Morphology, Seed Moisture, Seed Germination.

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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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