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2018 - 201912020 - 20232
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Author: Rajwinder Kaur × Start date: 2017 × Type: Thesis ×
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    ThesisItemEmbargo
    Biological control of Sclerotinia sclerotiorum causing stem rot disease of sunflower using bacterial endophytes
    (Punjab Agricultural University, Ludhiana, 2023) Rajwinder Kaur; Vyas, Pratibha; Vyas
    The aim of present study was to screen antagonistic bacterial endophytes against Sclerotinia sclerotiorum causing stem rot disease in sunflower. A total of 42 bacterial endophytes were acquired from the Department of Microbiology and Sclerotinia sclerotiorum from the Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana. Out of 42 bacterial isolates, four isolates exhibited antagonistic activity varying from 20.0 to 36.6% in dual plate assay and 35.4 to 92.0% in liquid media against S. sclerotiorum. The effect of bacterial endophytes on the ultrastructure of S. sclerotiorum was observed by scanning electron microscopy (SEM) which showed thinning, rupturing, breakage and shrinkage of the fungal hyphae in micrographs. In addition to antagonistic activity, bacterial endophytes also exhibited phosphate solubilization, and production of siderophores, HCN, auxins, ammonia, lipase, cellulose and amylase, while tested negative for protease, pectinase and xylanase production. Based on morphological features, biochemical test and MALDI-TOF-MS analysis, the isolates were identified as Sphingobacterium spiritivorum EB1, Bacillus sp. EB6, Pseudomonas aeruginosa EB21 and Serratia liquefaciens EB23. All the four bacterial strains exhibited ability to produce different volatile organic compounds with the highest number of VOCs produced by Bacillus sp. EB6 and the least by Pseudomonas aeruginosa EB21. The SEM analysis showed the colonization of the plant tissues by all the four bacterial strainsvalidating their endophytic nature. The bacterial treatments singly or in combinations also significantly enhanced the vigour index of sunflower ranging from 250 to 630.5. A significant increase in growth parameters, chlorophyll content, and nutrient content of shoot and soil was also observed with the bacterial treatments singly or in combinations over the uninoculated control in sunflower grown in pots in glasshouse conditions. The disease control by the bacterial treatments varied from 66.7 to 88.9%. The results indicated that the consortium of four strains was statistically not different from the consortium of SsEB1+ BaEB6 +SlEB23, indicating thereby the potential of these strains as potential biocontrol agent against Sclerotinia sclerotiorum. As the future line of recommendation, the formulation containing the consortium of these strains may be developed and tested in sunflower to control stem rot disease caused by Sclerotinia sclerotiorum in field conditions.
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    ThesisItemOpen Access
    Evaluation of old wheat lines for nutritional quality traits and protein profiling
    (Punjab Agricultural University, Ludhiana, 2021) Rajwinder Kaur; Bhardwaj, Rachana D.
    Thirty-four lines of ancient wheat and PBW550 as check variety were evaluated for nutritional quality traits, anti-nutritional factors and total antioxidant potential. The starch content lied in the range 52.56-68.5%. Total soluble proteins ranged from 7.28 in Triticum sphaerococcum (TS) 27 to 16.29% in TS 9. Amylose content ranged from 13.27 (TS 3) to 27.98% (TS 4) of starch content. Iron content was in the range 29.33-60 μg/g whereas Zinc varied from 30 to 61.5 μg/g. Tocopherol content ranged from 4.59 to 12.35 mg/g. Sona Moti, Nanne Samrat and Sugar free depicted higher contents of starch, amylose, protein, antioxidant capacity and lower contents of saponins. TS 19 lied in the high range of proteins, antioxidant potential, medium/high range of albumin-globulin and amphiphilic fractions and lower range of glutens and saponins. TS 26 had higher contents of tocopherol and total soluble proteins with more of albumin-globulin and amphiphilic fractions and less of glutens. Therefore, Sona moti, Nanne Samrat, Sugar free, TS 19 and TS 26 possessed better nutritional quality traits in contrary to modern cultivars.
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    ThesisItemOpen Access
    Population dynamics, distribution and rind disorder of mites and thrips on citrus in Punjab
    (Punjab Agricultural University, Ludhiana, 2018) Rajwinder Kaur; Bhullar, Manmeet Brar
    The studies on “Population dynamics, distribution and rind disorder of mites and thrips on citrus in Punjab” were conducted at three locations namely Fruit Research Farm, Punjab Agricultural University, Ludhiana; Regional Research Station, Abohar and Department of Horticulture (Punjab), Hoshiarpur (Bhunga). During the present study eight mite species namely Brevipalpus phoenicis (Geijskes), B. californicus (Banks), Tetranychus urticae Koch, Eutetranychus orientalis (Klein), Polyphagotarsonemus latus (Banks), Amblyseius (Euseius) alstoniae Gupta, A. (Euseius) finlandicus (Oudemans) and Cunaxa setirostris (Hermann) were observed on leaves, B. phoenicis was also observed on fruits from May onwards with maximum population in November - December. There was a negative correlation between mite abundance and rainfall at all locations. The mite families viz. Tenuipalpidae, Tarsonemidae and Cunaxidae had negative correlation with temperature and positive correlation with maximum R.H. but Tetranychidae had positive correlation with temperature and negative with maximum relative humidity. Citrus thrips, Scirtothrips citri (Moulton), started appearing in first week of March with the initiation of flowering and their attack continued up to last week of May. The population of citrus thrips increased progressively with increase in temperature and decrease in relative humidity. Maximum population of citrus thrips and mite species was observed in the arid zone (Abohar) followed by central zone (Ludhiana) and submontane zone (Hoshiarpur) of Punjab. Among all the mite species, E. orientalis and Amblyseius spp. were found to be widely distributed and recorded on all sampled fruit crops in Kinnow orchards. The study of alpha diversity indices showed that diversity and evenness indices were highest in Hoshiarpur (H’ = 1.32, Dmg = 1.42, E = 0.83), followed by Ludhiana (H’ = 1.27, Dmg = 1.32, E = 0.77) whereas lowest were observed in Abohar (H’ = 1.23, Dmg = 1.22, E = 0.73). The highest dominance indices were observed in Abohar (Simpson index = 0.37, d = 0.54). Results also indicated the dominance of B. phoenicis during November month at all the three locations. The experiments to study the impacts of rind disorder caused by mites, thrips and wind on various quality and biochemical parameters were conducted in the laboratory of Punjab Horticultural Postharvest Technology Center (PHPTC), Punjab Agricultural University, Ludhiana. The results showed that damaged fruits (rind scarring by mites and thrips) had less fruit firmness and lesser amount of ascorbic acid, phenols, pectin and carotenoids. But acidity, reducing sugar, total sugar and non reducing sugars were not affected due to rind scarring. However, TSS was higher in fruits having 50 per cent rind scarring as compared to healthy fruits but fully damaged fruits (75 - 100%) had less TSS. Wind damaged fruits had nonsignificant results or negligible differences between values of all physiochemical parameters of healthy fruits and wind scarred fruits. So it was concluded that these losses might be due to deterioration caused by only thrips and mites but not wind.