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Author: Amandeep Kaur × End date: 2014 × Start date: 2014 × Type: Thesis × Thesis Type: M.Sc ×
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    Variability in Fusarium oxysporum f.sp. ciceris, the incitant of chickpea (Cicer arietinum) wilt
    (2014) Amandeep Kaur; Sharma, Vineet K.
    Evolution of new races of Fusarium oxysporum f.sp. ciceris (Padwick) Matuo and K. Sato poses a serious threat to successful deployment of wilt resistant chickpea genotypes. Therefore, in the present study, 24 isolates of F. oxysporum f.sp. ciceris collected from different chickpea growing areas of Punjab and adjoining states were assessed for morphological, pathogenic and molecular variations. Among 24 isolates, the maximum (8.78 mm/days) and minimum (5.00 mm/day) growth rate were exhibited by Foc-21 and Foc -15, respectively. The isolates showed growth pattern from appressed, fluffy to less fluffy and mycelial colour varied from different shades of white to purplish white. A significant variation with respect to size of micro (8.9-16.9 x 3.1-6.3 µm) and macro (21.7-64.9 x 2.7-10.0 µm) conidia was also observed. At pathogenic level, Foc-3, Foc-7 and Foc-22 showed virulence pattern, similar to existing races 1, 2, 3 and 4 on three standard differentials viz. JG 62, WR 315 and L 550 whereas rest of the isolates did not match with any of the existing race reaction. Further, the six selected genotypes could differentiate the isolates into four pathotypes based on their aggressiveness and Foc-8 was found more aggressive (98.48 % wilt incidence) whereas Foc-24 was found least aggressive (7.22 % wilt incidence). The sequences of ITS genomic regions of 19 isolates showed 99 % similarity with Foc sequences by BLAST analysis. Furthermore, these 19 isolates converged into three groups based on ITS region sequence homology. Besides, a set of 91 wild derivative lines was also evaluated in wilt sick plot. Two derivative lines viz. GLW 59 and GLW 107 were found free from wilt and remaining 37 and 52 lines were found moderately resistant and susceptible to highly susceptible respectively.
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    ThesisItemOpen Access
    Antioxidative defense system and grain quality evaluation of heat tolerant wheat genotypes
    (Punjab Agricultural University, Ludhiana, 2014) Amandeep Kaur; Harinderjeet Kaur
    The fifty genotypes of wheat in two trials Multi Location Heat Tolerance (MLHT) I and Multi Location Heat Tolerance (MLHT) II under timely and late sown conditions were sown in experimental fields of Plant Breeding and Genetics during the crop season 2011-12 to study the impact of heat stress on physiological parameters. The chlorophyll content, canopy temperature depression, days to heading, peduncle length, plant height, grain number per spike, grain weight per spike, spike number per spike, total biomass and grain yield were affected negatively under late sown conditions in all genotypes except genotypes such as GW 433, HD 3090, MP 3353, WH 1124 and RW 3705 from MLHT I and HD 3040, HI 8703, MP 3304, DBW 14, DL788-2, HUW 234 and NW 2036 from MLHT II. Genotypes GW 433, HD 3090, MP 3353 and WH 1124 from MLHT I and HD 3040, HI 8703 and MP 3304 from MLHT II were found to be less susceptible to heat stress as reflected by lower values of heat susceptibility index. Genotypes HI 1571, PBW 670, RAJ 4250 and WH 1123 from MLHT I and HI 8703, PBW 639 and WHD 946 from MLHT II were found to be susceptible to high temperature due to higher values of heat susceptibility index. Total 25 genotypes (tolerant, susceptible and checks) from both trials MLHT I and MLHT II were selected for the study of antioxidative defense system and grain quality evaluation. Genotype WH 1124 from MLHT I and genotypes HD 3040 and HI 8703 from MLHT II showed increased activity of antioxidant enzymes such as superoxide dismutase, peroxidase, ascorbate peroxidase and catalase indicated better antioxidant defense system against heat stress and hence found to be the best among the selected tolerant genotypes. GW 433, HD 3090, HD 3040 and HI 8703 from both the trials MLHT I and MLHT II showed higher grain appearance score, test weight, grain hardness, protein content, SDS-sedimentation value, grain plumpness, total sugars, dry gluten content, gluten index and better starch pasting characteristics under late sown conditions, hence can produce better quality grains. Genotypes WH 1124, HD 3090, GW 433 and HD 3040, HI 8703 from the trials MLHT I and MLHT II exhibited better antioxidative defense system and superior quality characteristics with higher yield under heat stress.