1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Incorporation of resistance to bacterial wilt in indeterminate tomotoes(Department Of Olericulture, College Of Horticulture, Vellanikkara, 2002) Gudi Jacob; Sadhankumar, P GInvestigations on "Incorporation of resistance to bacterial wilt in indeterminate tomatoes" was carried out during July 2002 - September 2003 at the Department of Olericulture, College of Horticulture, Kerala Agricultural University, Vellanikkara. The salient findings are mentioned below: Three bacterial wilt resistant varieties (Sakthi, Mukthi and Anagha) were crossed with four indeterminate genotypes (BT 118-4-1-1, Sun 7611, TH 977 and Nidhi) in a line x tester fashion to produce twelve F 1 hybrids. The F 1 hybrids were found to be susceptible to bacterial wilt. All the hybrids except Sakthi x BT 118-4-1-1 were indeterminate in growth habit. The general combining ability of the parents and specific combining ability of the crosses were estimated. Anagha was a good general combiner for earliness in flowering, fruit set and harvest. BT 118-4-1-1 was a good general combiner for fruit yield per plant, fruits per plant and average fruit weight. Mukthi x Nidhi was the best specific combiner for fruit yield per plant. Sakthi x Nidhi was a good specific combiner for fruits per plant and Mukthi x TH 977 was a good specific combiner for average fruit weight. The relative heterosis and heterobeltiosis for different biometric characters were estimated. Sakthi x BT 118-4-1-1 was the best F 1 hybrid for fruit yield per plant (422.5 g plant") and average fruit weight (53.15 g). Mukthi x BT 118-4-1-1 was the best hybrid for fruits per plant (12.10). The F2 segregants were evaluated for bacterial wilt resistance and growth habit. There were 42 indeterminate F2 segregants resistant to bacterial wilt. Among these Anagha x BT 118-4-1-1 F2-13 was the earliest to harvest. Maximum fruit yield was obtained in the F2 segregant Mukthi x BT 118-4-1-1 F2-B. These indeterminate F2 segregants were selected for further improvement.Item Screening and biochemical characterization of tomato genotypes for resistance to bacterial wilt(Department Of Olericulture, College Of Horticulture, Vellanikkara, 1999) Subash Chandra Bose, S; Rajan, SInvestigation on 'Screening and biochemical characterization of tomato genotypes for resistance to bacterial' wilt' was carried out in the Department of Olericulture, and Biochemistry Laboratory, College of Horticulture, Vellanikkara 1 during 1997-99. The objectives of this study were to identify tomato genotypes resistant to bacterial wilt and to find the possibility for biochemical cataloguing of bacterial wilt resistant tomato genotypes. Evaluation for bacterial wilt resistance revealed that Sakthi, Mukthi and LE-474 were consistently resistant to bacterial wilt. Four additional sources of bacterial wilt resistance were identified, viz. LE-214, LE-415, LE-470 and LE-421. Based on the percentage wilting the twenty four genotypes included in this study were classified into four groups, viz. Resistant, Moderately Resistant, Susceptible and Highly susceptible. -.: All the bacterial wilt resistant and moderately resistant genotypes had a higher content of total phenols in roots and leaves at 45th and 60th day of plant growth; O.D. phenol content in roots of resistant varieties were higher than susceptible varieties. In leaf, the O.D. phenol content was high in moderately resistant genotypes at 45th and 60th day. All the genotypes were studied for isozyme variation with respect to two enzymes, viz. polyphenol oxidase and peroxidase. 10 general the roots had more number of bands compared to leaves at both the stages. '.. The root samples at 45th day showed two polyphenol oxidase bands, viz. PPO-I (~=0.074) and PPO-12 (Rm=0,414) which were specific to resistant varieties alone. This combination along with high total phenols may be considered as a biochemical marker for resistance to bacterial wilt in tomato. In 60 days old roots of resistant and moderately re istant genotypes the protein band PPO-9 (Rm=0.851) was predominantly present Regarding peroxidase, 45 . days old leaf samples had a combination of protein bands, viz. PRX-7 (Rm=0.361) and PRX-8 (Rm=O.382) in resistant and moderately resistant varieties. But at 60 days the roots and leaves did not show any specific band for resistance. In general at 45 days both leaf and root samples had more number of bands for polyphenol oxidase and peroxidase in resistant varieties compared to susceptible varieties. The study revealed that it was possible to arrive at a combination of specific isozyme bands at a particular growth stage, which can be used as a marker for bacterial wilt resistant tomato genotypes.