HETEROSIS AND COMBINING ABILITY STUDIES USING CYTOPLASMIC MALE STERILITY IN CAULIFLOWER (Brassica oleracea L. var. botrytis L.)
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Date
2021-03
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UHF,NAUNI
Abstract
ABSTRACT
The present investigation entitled “and Combining Ability Studies Using Cytoplasmic Male
Sterility in Cauliflower (Brassica oleracea L. var. botrytis L.)”was conducted during the years 2018-2020 at
research farm of Department of Vegetable Science, Dr YS Parmar University of Horticulture and Forestry, Nauni,
Solan (HP) to assess the information on gene action as inferred from the combining ability analysis and magnitude of
heterosis for different yield related traits. Thirty cross combinations generated from crossing of three CMS lines
(UHF-CAU-CMS-1, UHF-CAU-CMS-2, UHF-CAU-CMS-3) with 10 testers (PSBK-1, PSBKT-25, Early Snowball,
Cambridge No. 5, Olympus, Snowball Super, White Heart, Champion, Early London, White Rock) in Line × Tester
mating design were evaluated along with parents and a check (Pusa Snowball Hybrid-1) in randomized complete
block design (RCBD) with three replication. The genotypes and crosses were evaluated for various quantitative traits
viz., plant height, days to 50 per cent curd harvesting, number of leaves per plant, leaf length, leaf breadth, plant
spread, stalk length, curd equatorial length, curd polar length, curd size index, curd solidity, gross plant weight,
marketable curd weight, marketable curd yield, net curd weight, , harvest index and disease parameters such as
Sclerotinia rot incidence and black rot severity. The quality traits such as leaf attitude, leaf shape, leaf colour, leaf
waxiness, curd covering by inner leaves, curd knobbing, curd texture, curd shape, curd doming, curd colour, curd
riceyness and curd anthocyanin at the time of maturity were also recorded on basis of DUS characterization. Analysis
of variance for the data revealed significant differences among the genotypes for most of the traits investigated. The
combining ability analysis revealed significant differences due to lines, testers and line x tester interactions
for most of the traits when tested against error indicating appreciable diversity in the experimental material.
The experimental results revealed UHF-CAU-CMS-1 as the best general combiner for various traits such as plant
height, leaf length, plant spread, curd polar length, curd size index, gross plant weight, marketable curd weight, while;
UHF-CAU-CMS-2 excelled with desirable GCA effects for traits viz., days to 50 per cent curd harvesting, leaf
breadth, curd equatorial length, curd solidity and net curd weight. The experimental results inferred that on the
basis of GCA analysis and mean performances, the parents, UHF-CAU-CMS-2 (Line) and PSBK-1, Early
London and Snowball Super (testers) were found superior for majority of yield contributing traits. The cross
combinations UHF-CAU-CMS-1 × Snowball Super, UHF-CAU-CMS-1 × PSBK-1 and UHF-CAU-CMS-2 × Early
London were the three best performing crosses on the basis of their per se mean performance, SCA analysis and
heterotic effects for majority of yield traits such as curd size index, marketable curd weight/curd yield, net curd weight
and its contributing traits. These crosses also exhibited less Sclerotinia rot incidence and black rot severity and had
desirable curd traits such as snow-white curds, curd covering by inner leaves, compact curds and were free from curd
riceyness. The estimates of variance ratio (σ2A/ σ2D) were less than unity for most of the traits substantiating the role
of non-additive gene action for the traits suggesting the exploitation of heterosis breeding for further improvement in
the mid-late and late maturity groups of cauliflower. Hence, these three cross combinations should be further
evaluated at multi-locations before releasing as a substitute of already existing hybrids of cauliflower.