Morphological and molecular characterization of indigenous mango (Mangifera indica L.) germplasm of Jammu region
Loading...
Date
2018-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sher-e-Kashmir University of Agricultural Sciences & Technology of Jammu, Jammu (J&K)
Abstract
The present investigation entitled “Morphological and molecular characterization of indigenous mango (Mangifera indica L.) germplasm of Jammu region’’ was carried out at Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu from 2014 to 2016. The characterization was carried out on forty two mango genotypes to estimate the extent of variability by morphological and molecular characterization using IPGRI descriptors (IPGRI, 2006) and 20 SSR markers. The descriptive data of morphological characters viz., tree, leaf, foliage, flowering, seed and stone characters showed a lot of variation among different accessions.
Among different accessions, JMV-1 had the maximum mean fruit weight (236.99 g) whereas, minimum fruit weight (38.62 g) was observed in JMKB-4. Maximum mean fruit length (95.21 mm) was recorded in accession JMV-1 whereas minimum fruit length (46.87 mm) was recorded in accessions JMKB-4. Fruit diameter varied from (38.10 mm) to (75.82 mm) with average mean value of (53.75±0.94 mm) in all the accessions. Maximum fruit diameter (75.82 mm) was recorded in accession JMV-1, while minimum mean fruit diameter was recorded in accession JMKB-4 (38.10 mm). Maximum mean pulp thickness (54.05 mm) was recorded in the accession JMV-1, while minimum mean pulp thickness (20.71 mm) was observed in JMKB-4. However, maximum pulp content (2.50) was observed in accession JMKB-12, while minimum pulp content was recorded in accession JMRe-4 (0.90).
Fruit weight showed positive significant correlation with fruit length (r = 0.73), fruit diameter (r = 0.78), pulp thickness (r = 0.78), pulp ratio (r = 0.72), stone length (r = 0.49), stone weight (r = 0. 43), seed length (r = 0.49 mm) and seed weight (r = 0.50). Pulp ratio was positively correlated with stone length (r = 0.32), seed length (r = 0.32) but was negatively correlated with stone width (r = -0.11), stone thickness (r = -0.16) and seed width (r = -0.16). The path analysis revealed that seed width (0.6395) had maximum positive direct effect on fruit weight followed by, fruit diameter (0.6230), pulp thickness (0.5850) and fruit length (0.3124). The maximum negative direct effect on fruit weight was shown by characters such as fruit skin thickness (- 0.7384) and pulp ratio (-0.5964). Maximum positive indirect effects on fruit weight was exhibited by pulp thickness (0.6101) via fruit diameter followed by pulp ratio (0.5846) via fruit diameter. The PCA for mango genotypes revealed maximum variation by the first two PC’s contributing 81.54% variance. PC1 and PC2 contributed total variance of 59.96 % and 21.58 %, respectively with total variance (1.54%). Out of four major PC’s, the first PC showed significant factor loadings for morphological traits viz., stone width (0.336), stone weight (0.335) and stone thickness (0.336) and seed weight (0.327) indicated 59.96 % of the total variance.
The dendrogram revealed that all 42 mango genotypes were grouped into three main clusters. Polymorphic Information Content (PIC) value ranged from 0.45 (SSR-8) to 0.62 (SSR-19). DNA fragments generated from simple sequence repeat (SSR) data ranged from 92 to 275 base pairs. Dissimilarity matrix using SSR data revealed that dissimilarity coefficients ranged from 0.05 (JMA-9 and JMRe-35) to 0.95 (JMV-1 and JMRe-3). Model based cluster analysis grouped 42 mango genotypes into 3 genetically distinct clusters (K = 3) with various degrees of admixtures.
From this study, it can be concluded that extreme diversity exists among different accessions of mango from different areas of Jammu region with respect to different morphological characters. Among 42 seedling trees, viz., JMA-1, JMRe-1, JMRe-7 and JMV-1 were having desirable characters as good fruit weight, attractiveness, more pulp content and less fibre content have been selected for sucking and eating type and can be recommended for multiplication in the Jammu province of J&K state. Molecular data showed that the genotypes JMV-1 and JMRe-3, JMRe-2 and JMRe-4, JMKb-11 and JMS-1 and JMRe-5 and JMKb-1 are most diverse among the group of 42 genotypes. Hence, it is recommended that these genotypes should be conserved and used for future breeding programme in Jammu region.
Description
Keywords
null