Thumbnail Image

Theses

Browse

20221
Reset filters
Subject: Vegetable Science × Author: Bhatt, Rajendra × Start date: 2020 ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Heterosis, combining ability and screening for red pumpkin beetle resistance in bottle gourd [Lagenaria siceraria (Molina) Standl.]
    (G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Bhatt, Rajendra; Raghav, Manoj
    Bottle gourd is one of the most widely grown cucurbitaceous crops in the world and is known as the versatile therapeutic crop in all vegetables. Exploitation of heterosis in bottle gourd is considered as most latent avenues for quantum increase in yield. Therefore, the present investigation was carried out to assess the heterosis and identify the best parent with promising single crosses for yield and its attributing characters and also identify the genotype for resistance against red pumpkin beetle (RPB). The observation on different agro- orphological characters were recorded on five randomly selected plants from each genotype and the appropriate statistical methods were used to draw the conclusion. A half diallel involving eight genotypes were used to produce twenty-eight hybrids at Vegetable Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, (Uttarakhand) during zaid 2021. All the thirty-eight genotypes including eight parents, twenty-eight F1s and two check variety were evaluated in a Randomized Block Design (RBD) with three replications during kharif season of 2021 and zaid season of 2022. The pooled mean data of parents and hybrids revealed that the parent P2 and hybrid P3 × P8 had observed maximum fruit yield. Among twenty-eight crosses, the sufficient degree of relative heterosis, heterobeltiosis and standard heterosis for fruit yield was observed in the top hybrids P4 × P5, P3 × P4, P3 × P8 and P1× P4 under pooled analysis. The assessed pooled data for analysis of variance for combining ability indicated that both additive and non- additive gene action were important for expression of different characters. The pooled estimates of σ² SCA were found to be higher than the corresponding σ2 GCA for all the characters under study indicating the presence of dominance gene action. The pooled analysis of GCA effects revealed that the parents P2, P3 and P5 were observed best general combiner for maximum characters under pooled analysis, where the parents P2 and P8 were observed the best general combiners for fruit yield. The hybrids P1 × P4 and P2 × P7 had good SCA effects for maximum characters under pooled analysis, where the hybrids P1 × P6, P2 × P5, P2 × P7, P5 × P8, P1 × P8, P2 × P4, P1 × P7, P4 × P5, P3 × P8, P1 × P4 and P3 × P4 exhibited good SCA effects for yield and yield attributing characters. The hybrids P3 × P4, P3 × P8 and P4 × P5 exhibited high per se performance along with good SCA effects for fruit yield, indicating the presence of both additive and non- additive gene action and hence, these hybrids may be utilized for heterosis breeding as well as for isolating the promising segregants in advanced segregating generations. During screening of thirty-eight genotypes for resistance against RPB, the results revealed that the population activity of RPB had significant positive correlation with the high temperature, leaf infestation and yield loss that’s why zaid season of 2022 was observed the high and longer peak period for population activity, leaf infestation and yield loss on different growth stages of crop, as compare to kharif season of 2021. The assessed data of leaf trichome and leaf biochemicals for the activity of RPB during both the seasons revealed that the number of trichomes, length of trichomes, total flavonoid, total phenol and total antioxidant were observed high in young leaf and showed less infestation of RPB, while total chlorophyll, total carotenoid and total protein were observed high in mature leaf and showed maximum infestation of RPB. On the basis of population activity and degree of damage on leaves, the genotypes P1 × P6, P1 × P8, P5 × P6 and P5 × P7 with check Arka Bahar were found resistant against RPB during both the seasons and these genotypes having ample scope towards the development of resistant varieties which is an important component for an integrated pest management and may work as a remedy for those areas where RPB is a major constraint in cultivation of bottle gourd