HETEROSIS STUDIES ON YIELD AND QUALITY TRAITS IN TEMPERATE CARROT (Daucus carota L.) USING CYTOPLASMIC MALE STERILE (CMS) LINES
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Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
DIVISION OF VEGETABLE SCIENCE ICAR- INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Abstract
Carrot belonging to plant family Apiaceae is one of the most widely consumed root crops rich in bioactive
compounds and phytochemicals. The variation in mitochondrial genome cytoplasm based 10 male sterile lines
was analyzed using mitochondrial (genome specific and mt-SSR) markers. The parental CMS lines and fertile
testers were crossed to develop 100 F1 K\EULGVLQOLQHîWHVWHUPDWLQJGHVLJQ 7KHUHVXOWLQJ WHVWFURVVSURJHQLHV
DORQJZLWK VWDQGDUGFKHFNVZHUHHYDOXDWHGLQZLWKWKUHHUHSOLFDWLRQVDW1DJJDU([SHULPHQWDO)DUPRI,&$5-
IARI, Regional Station, Katrain, Himachal Pradesh. As there has been increasing interest in pigmented carrots
rich in carotenoids and flavonoids as source of natural food dye. On account of antioxidant and anticancer
properties, the consumption of carrot and its by-products is increasing steadily. Hence, to meet the increasing
demand with superior horticultural and quality traits, the identification of ideal parental chemotypes or inbreds of
carrot with desirable combining ability is of utmost importance for the generation of quality cultivars. The petaloid
type cytoplasmic male sterility (pt-CMS) has been instrumental in developing heterotic hybrids in carrot. In this
context, the 10 pt-CMS lines of temperate carrot developed after more than nine generation of backcrossing were
crossed with 10 inbreds used as testers in line îWHVWHUPDWLQJGHVLJQWRJHQHUDWH WHVWFURVVSURJHQLHV 7KH
resulting 100 hybrids along with 20 parental types and commercial checks were evaluated for thirteen horticultural
traits and eight different bioactive compounds consecutively for two years. The pooled estimates of variance
DQDO\VLVRYHUWKH\HDUVUHYHDOHGVLJQLILFDQWPHDQVTXDUHVRIOLQHV WHVWHUVDQGOLQHîWHVWHUV ZKLFKLQGLFDWHGWKH
influence of both additive and non-additive gene effects in the expression. The pooled analysis estimates of per
se performance, principal component analysis and dendrogram analysis over the years indicated remarkable
genetic variation among the parental types for their exploitation in heterosis breeding. The higher magnitude of
ı2
sca DVFRPSDUHGWRı2
gca highlighted the relevance of specific combining ability in the generation of heterotic
crosses for both horticultural and bioactive compounds. The CMS lines KT-8542A (3.54**) , KT-98A (1.15**)
and KT-28A (0.59) were good combiner for root yield . CMS lines viz. KT-8542A (1.92**) could be better as
female parent for higher root length. CMS lines KT-10A (5.93**), for cortex thickness and core diameter KT8542A(25.33**) and could be utilized as parents for developing hybrids with thick flesh and coreless roots. The
crosses KT- [31-1, KT- [1HZNXURGDcan be recommended for further evaluation trial for developing
hybrids with higher marketable roots and its contributing traits. 7KHVLJQLILFDQW\HDUîJHQRW\SHLQWHUDFWLRQIRU
WKH7&&DQGȕ-carotene content revealed the role of few major genes controlling expression of carotenoids in
carrot root. The positive association of SCA with heterosis indicated the influence of non-additive gene effects in
controlling the expression of traits. The significant genotype î HQYLURQPHQW LQWHUDFWLRQ YDULDQFH IRU WRWDO
FDURWHQRLGDQGȕ-carotene indicated the role of both genotype and environment controlling expression of these
traits, which necessitated the need of multi-year and multi-environment evaluation for the selection of genotypes
for carotenoid content. The pooled analysis results also determined that the carotenoid content in carrot root is
under the genetic control of few major genes (oligogenic). The high estimates of h2
ns over the years for carotenoid
DQGȕ-carotene indicated that selection would be effective for these traits. GCA effects over the years CMS lines
KT-28A (2.75***) and KT- $
VKRZQ JRRG JHQHUDO FRPELQHU IRU ȕ-carotene and total carotenoid
content respectively, KT-98A (0.45***) for CUPRAC, KT-80A (0.08***) for FRAP, and KT-8542A (87.81***)
for phenols could be used as parents in hybrid breeding programs. The significantly highest heterosis for phenolic
content in desirable direction was observed in the 15.38 % (KT-98 x KS-59) to 1546.38 % (KT-62 x KS-21) mid
parent. The hybrid 6.15% (KT-10 x KS-50) to 320.60% (KT-62 x KS-21) and 8.03 % (KT- [31-1) to 225.10
% (KT- [3<-1), respectively exhibited significantly highest heterosis over both mid parent and better parent
in desirable direction for beta–carotene content. Significantly high total carotenoid content over the mid parent
and better parent heterosis was observed, 6.76 % (KT-62 x KS-20) to 390.38% (KT-28 x KS-59) and 19.18%
(KT- [ 3<-1) to 312.88 % (KT- [ 3<-1), respectively The molecular analysis revealed that Out of 100
microsatellite primers, 67 primers showed high polymorphism among the parental lines. The PIC content ranged
from 0.35 to 0.86 and genetic distance varied from of 0.46 to 0.89, found significant association of genetic distance
based on polymorphic genomic-SSR with heterosis for commercial traits indicated the utility of genetic distances
in prediction of heterosis in carrot. Moreover green petal colour and light green petaloid were predominant in
CMS lines, encountered variation in their mid-ribs. Variation in petaloid shape and colour pattern could may be
due to influence of genetic background of the transformed CMS lines, however, it need further investigations. The
overall results obtained would be instrumental for carrot breeders, geneticists and food scientists for enhancing
potential of carrot for agro-food, pharmaceutical and natural pigment industry.
Description
T-10487