http://www.erepo.iihr.ernet.in/handle/123456789/505 2013-05-15T16:17:12Z 2013-05-15T16:17:12Z Hemalata Singh http://www.erepo.iihr.ernet.in/handle/123456789/512 2012-11-29T20:30:06Z 2011-01-01T00:00:00Z

Title: Biochemical studies on the development of aril browning in pomegranate Authors: Hemalata Singh Abstract: Aril browning (AB) in pomegranate is a physiological disorder free of external symptoms. Browning of aril starts with a dark dot on the aril and spreads further to the entire aril. The incidence is at first observed at 50% fruit maturity near the calyx end just under the skin. Present studies showed that AB incidence was higher in panicles as compared to those on main shoots. Fruits exposed to sun showed lesser incidence. AB incidence also increased with fruit maturity. Biochemical studies revealed that sugars, TSS, starch and pH were higher in AB affected aril as compared to healthy arils whereas anthocyanin, polyphenols, titratable acidity, protein and ascorbic acid were less in AB affected aril. Enzyme activities like amylase, total dehydrogenase activity in seed were reduced in seed of AB affected aril compared to healthy, whereas enzyme activity like polyphenol oxidase was more in seed of AB affected aril as compared to seed of healthy aril. Healthy arils showed higher moisture content and the seed higher percentage and faster rate of germination as compared to seed of AB affected aril, revealing that seed of AB affected aril had lost moisture leading to reduction in seed viability. Field experiments with growth regulators showed that GA3 treatment reduced incidence of AB and PBZ treatment increased the incidence of browning as compared to control. These findings indicated that the development of AB in pomegranate is a result of combination of many factors like inter fruit competition, biochemical and physiological changes in aril during fruit growth.

2011-01-01T00:00:00Z Jayashree Ugalat http://www.erepo.iihr.ernet.in/handle/123456789/511 2012-11-29T20:30:06Z 2010-01-01T00:00:00Z

Title: Biochemical changes in seed in relation to corky tissue development of sapota [Manikara achras (Mill.) Fosberg] Authors: Jayashree Ugalat Abstract: Corky tissue is a physiological disorder affecting Cricket Ball variety of sapota to the tune of 50% or more especially in the summer season. The affected fruits do not show any external symptoms and becomes apparent only after the fruit is cut open. Corky tissue affected fruits are characterized by a hard lump within the pulp and are less sweet to taste and in extreme cases the fruits give out a unpleasant odour. As such, the corky tissue affected fruits become unit for consumption. Very little work has been reported so far on the biochemistry of the disorder. Studies conducted tin this work showed that CT incidence increased with increasing number of fruits per panicle. GA3 treated fruits showed lower incidence of CT as compared to control and PBZ treatment increased the incidence of CT. CT incidence increased in fruits harvested during summer season (Mar- April) as compared to winter season (Nov-Dec) and similarly incidence was more under rain fed treatment as compared to irrigated treatment. Radio tracer experiment showed there was an increased flow of water away from the fruit to shoot during CT formation. Biochemical studies revealed that in CT affected fruit pulp, reduced sugars, total soluble sugars, proteins, fatty acids, mineral nutrients and enzyme activities like amylase, lipase were reduced and starch content was higher as compared to healthy fruit pulp. And in case of seeds of corky tissue affected fruits, protein, free fatty acids, starch and enzyme activity like total dehydrogenase, lipase and germination percentage showed decreasing trend, but reducing and total soluble sugars content were higher compared to seeds from healthy fruit. These above findings, indicated the dominant role of competition among different sinks and loss of viability of seeds in the induction of CT in sapota

2010-01-01T00:00:00Z S, Renuka http://www.erepo.iihr.ernet.in/handle/123456789/510 2012-11-29T20:30:06Z 2009-01-01T00:00:00Z

Title: Induction of systemic acquired resistance in tomato inoculated with early leaf blight pathogen Authors: S, Renuka Abstract: The results of this study provide evidence that application of simple non-toxic chemical solutions such as potassium phosphate can control early blight of tomato, Their low toxicity to animals, comparative environmental safety and nutrient value make them ideal foliar fertilizers which can be used for application in the field for disease control. The ability of potassium phosphate to induce high levels of three defence enzymes and four antioxidants in tomato leaf could be of use in elicitation of SAR in disease management programme. Thus potassium sulphate spray to tomato plants can provide a degree of protection to tomato plants against early leaf blight and help in disease control.

2009-01-01T00:00:00Z Jaya Joshi http://www.erepo.iihr.ernet.in/handle/123456789/509 2012-11-29T20:30:05Z 2009-01-01T00:00:00Z

Title: Biochemical studies on the development of corky tissue in sapota [Manikara achras (Mill.) Fosberg] Authors: Jaya Joshi Abstract: Corky tissue (CT) of sapota is a physiological disorder characterized by hard lump in the pulp, slightly desiccated in nature and acidic to taste. This disorder shows no distinct external symptoms and becomes visible only when fruit is cut open. Under extremely severe conditions, corky skin eruptions are seen. Corky tissue incidence is estimated to vary from 20 to 50 per cent in Cricket Ball, while in other varieties like Kalipati it is up to 5 per cent. Biochemical analysis revealed that total and reducing sugars, soluble protein and activities of amylase and lipase were higher in the mesocarp of healthy fruits compared to CT affected fruits, while content of starch and free amino acids were lower. These indicated that degradation of starch into sugars was hampered in CT affected fruits. Starch content, soluble protein and free amino acid were higher in healthy seeds than seeds from CT affected fruits, while total and reducing sugars and amylase activity were lower. Under field conditions, regulation of sink strength by exogenous application of GA3 and PBZ showed that, CT occurred in the weaker sink thus confirming the role of itner-fruit competition in CT development. Seed viability seems to play an important role in CT development. Sink strength of fruit depends upon number of viable seeds it has. Moisture content in seed and mesocarp of healthy fruits was higher in comparison with that of CT affected fruits, showing thereby that seed from CT affected fruits had lost moisture leading to reduction in seed viability. Reduction in seed viability in corky tissue affected fruit was confirmed by data on germination, dehydrogenase activity, DNA content and analysis of endogenous levels of GA3, ABA and JA using HPLC. Conditions of increased temperature, evaporative demand and decreased relative humidity showed marked increase in corky tissue incidence.

2009-01-01T00:00:00Z