21.09.2015 Views

The Journal of Research ANGRAU

Contents of 41(1) 2013 - acharya ng ranga agricultural university

Contents of 41(1) 2013 - acharya ng ranga agricultural university

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

<strong>Research</strong> Notes<br />

J.Res. <strong>ANGRAU</strong> 41(1) 109-113, 2013<br />

GENETIC DIVERGENCE STUDIES FOR YIELD AND PHYSIOLOGICAL<br />

ATTRIBUTES IN GROUNDNUT (Arachis hypogaea L.)<br />

D. NIRMALA, V. JAYALAKSHMI, B. NARENDRA and P. UMAMAHESHWARI<br />

Deptartment <strong>of</strong> Genetic & Plant Breeding, Agricultural College, <strong>ANGRAU</strong>, Mahanandi – 518 503<br />

Date <strong>of</strong> Receipt : 07.06.2012 Date <strong>of</strong> Acceptance : 26.12.2012<br />

Selection <strong>of</strong> genotypes from the available<br />

genetic variation is crucial for any crop improvement<br />

programme. Estimating genetic diversity available in<br />

the existing germplasm provides clue to the choice<br />

<strong>of</strong> most desirable parents for use in hybridization<br />

programmes. Selections based on physiological traits<br />

that confer water use efficiency have been suggested<br />

for improving drought tolerance in Groundnut. In the<br />

present investigation an attempt was made to identify<br />

most diverse groundnut genotypes for practical plant<br />

breeding programmes utilizing physiological traits like<br />

SPAD Chlorophyll Metre Reading (SCMR), specific<br />

leaf area, crop growth rate (CGR), relative growth rate<br />

(RGR) etc.<br />

Thirty genotypes <strong>of</strong> Groundnut were<br />

evaluated during Kharif 2011 at Agricutural College<br />

Mahanandi, A.P. <strong>The</strong> experimental material was<br />

procured from the Groundnut Breeding Station,<br />

RARS, Tirupati comprising <strong>of</strong> diverse breeding<br />

material generated in All India Coordinated Groundnut<br />

Improvement Programme. <strong>The</strong> experiment was laid<br />

out in a Randomized Block Design replicated thrice.<br />

Each genotype in a replication was grown in two rows<br />

<strong>of</strong> 4.2 m length with a spacing <strong>of</strong> 30 cm between the<br />

rows and 10 cm within a row. All the recommended<br />

package <strong>of</strong> practices were followed to raise a good<br />

crop. Observations were recorded on five randomly<br />

chosen plants in each genotype in a replication for<br />

19 characters. <strong>The</strong> data collected was analyzed as<br />

per the standard procedures described by<br />

Mahalanobis’s (1936) and Rao (1952).<br />

Analysis <strong>of</strong> variance for both quantitative and<br />

physiological traits in all the 30 genotypes under study<br />

revealed significant differences for all the characters<br />

indicating the wealth <strong>of</strong> variability available in the<br />

germplasm. Further the data was subjected to D 2<br />

analysis and the results were presented in<br />

Table 1 to 3.<br />

Based on D 2 analysis all the 30 genotypes<br />

were grouped into 14 clusters with a variable number<br />

<strong>of</strong> entries in each cluster revealing the presence <strong>of</strong> a<br />

considerable amount <strong>of</strong> genetic diversity in the<br />

material (Table 2). Cluster I had maximum number<br />

<strong>of</strong> 10 genotypes followed by cluster II with 6<br />

genotypes and cluster X with 3 genotypes. Remaining<br />

all other clusters possessed one genotype each.<br />

Cluster I alone had one-third <strong>of</strong> the total genotypes<br />

studied indicating that the genotypes under study had<br />

narrow genetic diversity among them. Similarity in<br />

the base population from which they have been<br />

evolved might be the cause <strong>of</strong> genetic uniformity.<br />

However, the uni-directional selection potential for<br />

one particular character or a group <strong>of</strong> linked traits in<br />

several places may produce similar phenotypes which<br />

can be aggregated into one cluster irrespective <strong>of</strong><br />

geographical diversity. Sudhir Kumar et al (2010),<br />

Awatade (2007) and Garajappa et al. (2005) reported<br />

that there is no correlation between genetic diversity<br />

and geographical diversity in the groundnut genotypes<br />

studied by them.<br />

Average inter cluster and intra cluster D 2<br />

values among the 30 genotypes were furnished in<br />

Table 2. <strong>The</strong> maximum intra cluster distance was<br />

recorded for cluster X (6.31) followed by cluster II<br />

(5.13) and cluster I (4.95) revealing substantial<br />

diversity within the clusters. Maximum inter-cluster<br />

values were observed between cluster III and cluster<br />

XII (12.35) followed by cluster V and cluster XIII<br />

(12.10) indicating maximum divergence between the<br />

genotypes included in these clusters.<br />

Cluster means for all the traits were given in<br />

Table 2. Cluster means for different characters<br />

indicated that none <strong>of</strong> the clusters contained genotype<br />

with all the desirable characters and so recombinant<br />

breeding between genotypes <strong>of</strong> different clusters is<br />

needed. Cluster XII showed higher cluster means for<br />

email: veera.jayalakshmi@gmail.com<br />

114

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!