The experiment was laid out in randomized complete block design (RCBD) with three replications. Thirty genotypes were evaluated for various quantitative and quality traits. Analysis of variance revealed significant differences among genotypes for all the traits. The maximum fruit yield plant-1 was recorded in Shalimar improved (7.57 kg) followed by SH-BG-72 (7.30 kg), SH-BG-17 (7.28 kg) and minimum in SH-BG-53 (4.32 kg). The estimates of phenotypic coefficient of variance were slightly higher than the corresponding genotypic coefficient of variance for all the characters studied indicating the little influence of environment in the expression of these traits.
The highest phenotypic and genotypic coefficients of variation were observed for fruit diameter (35.65 and 34.62) followed by total chlorophyll (30.08 and 20.02) and fruit length (23.70 and 23.44). High heritability coupled with high genetic gain was recorded for fruit length (0.97 and 47.74), fruit diameter (0.94 and 71.73), total sugars (0.74 and 24.05) and dry matter content (0.84 and 25.42) indicating that the heritability is most likely due to additive gene effects and thus the chances of fixing by selection are more. Fruit yield plant-1 was positively associated with traits like node number at which first male flower appeared, node number at which first female flower appeared, number of days to anthesis of first female flower, fruit diameter, dry matter content and total sugars.
Moreover the traits like days to last fruit harvest and number of fruits plant-1 showed significant positive genotypic correlation with fruit yield plant-1 indicating that direct selection of these traits will be effective. Path coefficient analysis revealed appreciable amount of direct positive effects of component traits like node number at which first male flower appeared, days to anthesis of first female flower, days to last fruit harvest, number of fruits plant-1, fruit weight plant-1 and total sugars on fruit yield plant-1. D2 statistics grouped thirty genotypes of bottle gourd into three clusters. Cluster I had maximum number of genotypes (25) followed by cluster II (4) and cluster III (1).
Table of Contents
1. INTRODUCTION
2. REVIEW OF LITERATURE
2.1 Genetic Variability
2.2 Heritability and genetic gain
2.3 Correlation and path coefficient analysis
2.4 Genetic divergence
3. MATERIALS AND METHODS
3.1 Experimental material
3.2 Characters studied and observational procedures
3.3 Statistical and biometrical analysis
4. EXPERIMENTAL FINDINGS
4.1 Mean performance and Analysis of variance
4.2 Coefficient of variability, heritability and genetic gain
4.3 Correlation coefficient
4.4 Path coefficient analysis
4.5 Estimation of genetic divergence
4.6 Percent contributon of traits
5. DISCUSSION
5.1 Mean performance of genotypes
5.2 Genetic variability, heritability and genetic gain (genetic advance as per cent of mean)
5.3 Correlation coefficients
5.4 Path coefficient analysis
5.5 Genetic diversity
6. SUMMARY AND CONCLUSION
Research Objectives and Focus
The study investigates the genetic variability, heritability, and divergence in bottle gourd genotypes to identify superior breeding lines for crop improvement, specifically focusing on yield-related traits and their interrelationships.
- Assessment of genetic variability in yield and quality attributes among 30 bottle gourd genotypes.
- Evaluation of heritability and genetic gain for various morphological and quantitative traits.
- Determination of phenotypic and genotypic correlations between yield components and fruit yield.
- Path coefficient analysis to identify direct and indirect effects of traits on fruit yield.
- Genetic divergence analysis using Mahalanobis D2 statistics for parent selection in hybridization.
Excerpt from the Book
3.1 Experimental material
Thirty diverse genotypes of bottle gourd were evaluated for various yield and yield attributing traits at the Experimental field of the Division of Vegetable science SKUAST-K Shalimar Srinagar, during Kharief 2018. The names of the genotypes along with their source are given in the Table-1. A single factor experiment was laid out in randomized complete block design (RCBD) with three replications of each accession per plot. The whole experimental area was divided into three blocks (experimental units) each of which was then divided into thirty rows to represent the thirty treatments. Seeds from each genotype were sown at random to each block at spacing of 1 m between rows and 0.60 m between seed to seed. Recommended package of practices were adopted to raise a healthy crop.
Summary of Chapters
1. INTRODUCTION: Provides an overview of bottle gourd's origin, economic importance, nutritional value, and the necessity for genetic improvement through breeding.
2. REVIEW OF LITERATURE: Examines previous research regarding genetic variability, heritability, correlation, path analysis, and genetic divergence in bottle gourd and related crops.
3. MATERIALS AND METHODS: Details the experimental setup, location, materials used, and the statistical methodologies employed for data analysis.
4. EXPERIMENTAL FINDINGS: Presents the results of the analysis of variance, trait variability, correlation studies, and genetic divergence among the thirty genotypes.
5. DISCUSSION: Interprets the experimental results, comparing them with existing literature and highlighting the implications for breeding programs.
6. SUMMARY AND CONCLUSION: Recaps the major findings of the investigation and provides concluding recommendations for future breeding efforts.
Keywords
Correlation, Clusters, Divergence, Genetic gain, Heritability, Variability, Bottle gourd, Breeding, Yield, Genotypes, Path analysis, Phenotypic, Genotypic, Morphology.
Frequently Asked Questions
What is the fundamental objective of this research?
The primary goal is to study genetic divergence and variability among thirty bottle gourd genotypes to facilitate the selection of superior parents for effective hybridization programs.
What are the central themes covered in the study?
The study focuses on genetic variability, heritability, correlation between yield components, path coefficient analysis, and genetic diversity clusters.
What is the primary research question?
The research seeks to determine how diverse genotypes can be clustered based on their quantitative traits to optimize selection for high-yielding bottle gourd varieties.
Which scientific methods were applied?
The study utilized a randomized complete block design (RCBD), ANOVA for variance, and Mahalanobis D2 statistics for grouping genotypes into clusters.
What does the main body of the work address?
It covers the experimental findings on mean performance, trait correlations, direct and indirect effects of yield components, and the resulting genetic divergence among genotypes.
Which keywords define this work?
Key terms include Genetic divergence, Heritability, Yield components, Path analysis, and Bottle gourd [Lagenaria siceraria].
How were the bottle gourd genotypes categorized?
The genotypes were categorized into three distinct clusters using the Tocher method based on their genetic distances calculated from Mahalanobis D2 statistics.
Which traits contributed most to the genetic divergence?
Fruit length was identified as the primary factor contributing to genetic divergence, accounting for approximately 32.41% of the variation.
- Citar trabajo
- Majid Rashid (Autor), 2020, Genetic Divergence Studies in Bottle Gourd. The Plant Lagenaria Siceraria, Múnich, GRIN Verlag, https://www.grin.com/document/915342
