Heterosis Combining ability and Screening for Red Pumpkin Beetle Resistance in Bottle gourd Lagenaria siceraria Molina Standl

Abstract

Bottle gourd is one of the most widely grown cucurbitaceous crops in the world and is known newlineas the versatile therapeutic crop in all vegetables. Exploitation of heterosis in bottle gourd is considered newlineas most latent avenues for quantum increase in yield. Therefore, the present investigation was carried newlineout to assess the heterosis and identify the best parent with promising single crosses for yield and its newlineattributing characters and also identify the genotype for resistance against red pumpkin beetle (RPB). newlineThe observation on different agro-morphological characters were recorded on five randomly selected newlineplants from each genotype and the appropriate statistical methods were used to draw the conclusion. A newlinehalf diallel involving eight genotypes were used to produce twenty-eight hybrids at Vegetable Research newlineCentre, G. B. Pant University of Agriculture and Technology, Pantnagar, Udham Singh Nagar, newline(Uttarakhand) during zaid 2021. All the thirty-eight genotypes including eight parents, twenty-eight F1s newlineand two check variety were evaluated in a Randomized Block Design (RBD) with three replications newlineduring kharif season of 2021 and zaid season of 2022. newlineThe pooled mean data of parents and hybrids revealed that the parent P2 and hybrid P3 × P8 newlinehad observed maximum fruit yield. Among twenty-eight crosses, the sufficient degree of relative newlineheterosis, heterobeltiosis and standard heterosis for fruit yield was observed in the top hybrids P4 × newlineP5, P3 × P4, P3 × P8 and P1× P4 under pooled analysis. The assessed pooled data for analysis of newlinevariance for combining ability indicated that both additive and non- additive gene action were newlineimportant for expression of different characters. The pooled estimates of and#963;² SCA were found to be newlinehigher than the corresponding and#963;2 GCA for all the characters under study indicating the presence of newlinedominance gene action. The pooled analysis of GCA effects revealed that the parents P2, P3 and P5 newlinewere observed best general combiner for maximum characters under pooled analysis, where the newlineparents P2 and P8 were observed the best general combiners for fruit yield. The hybrids P1 × P4 and newlineP2 × P7 had good SCA effects for maximum characters under pooled analysis, where the hybrids P1 × newlineP6, P2 × P5, P2 × P7, P5 × P8, P1 × P8, P2 × P4, P1 × P7, P4 × P5, P3 × P8, P1 × P4 and P3 × P4 exhibited newlinegood SCA effects for yield and yield attributing characters. The hybrids P3 × P4, P3 × P8 and P4 × P5 newlineexhibited high per se performance along with good SCA effects for fruit yield, indicating the newlinepresence of both additive and non- additive gene action and hence, these hybrids may be utilized for newlineheterosis breeding as well as for isolating the promising segregants in advanced segregating newlinegenerations. During screening of thirty-eight genotypes for resistance against RPB, the results newlinerevealed that the population activity of RPB had significant positive correlation with the high newlinetemperature, leaf infestation and yield loss that s why zaid season of 2022 was observed the high and newlinelonger peak period for population activity, leaf infestation and yield loss on different growth stages newlineof crop, as compare to kharif season of 2021. The assessed data of leaf trichome and leaf biochemicals newlinefor the activity of RPB during both the seasons revealed that the number of trichomes, newlinelength of trichomes, total flavonoid, total phenol and total antioxidant were observed high in young newlineleaf and showed less infestation of RPB, while total chlorophyll, total carotenoid and total protein newlinewere observed high in mature leaf and showed maximum infestation of RPB. On the basis of newlinepopulation activity and degree of damage on leaves, the genotypes P1 × P6, P1 × P8, P5 × P6 and P5 × newlineP7 with check Arka Bahar were found resistant against RPB during both the seasons and these newlinegenotypes having ample scope towards the development of resistant varieties which is an important newlinecomponent for an integrated pest management and may work as a remedy for those areas where RPB newlineis a major constraint in cultivation of bottle gourd. newline( newline