Indian Society of Genetics & Plant Breeding
With global increase in temperature, terminal heat stress
(THS) has emerged as a major challenge in food crops.
Indian mustard (Brassica juncea L. Czern & Coss), C3 plant,
grows well at 15-20°C. Heat stress at seedling as well as at
flowering stage leads to enhanced vegetative growth and
flower abortion leading to loss in seed yield. Late sowing
after cotton and rice harvest expose the crop to high
temperature stress during reproductive stage of
development. A fixed diversity stock of 486 Indian mustard
lines were evaluated under delayed planting conditions to
expose the crop to THS for two consecutive years. Selection
indices were computed using four different combinations
of traits via Kang_SAS Path computer program along with
expected genetic advance (GA) at 5% selection intensity.
Set1, comprised of five traits viz., plant height (PH), number
of secondary branches (NSB), number of siliquae on main
shoot (NSMS), seed yield (SY) and 1000-seed weight (TSW)
were recorded the highest GA (8.612) in comparison to
other trait combinations tested in present study. Other
important finding was slight difference in GA of set I (8.612;
SY included) and set II (8.599; SY excluded) with efficiency
of selection index 131% and 130%, respectively. This
recommended that in initial breeding generations (F2/F3), a
breeder may base his selection on four yield related traits
(PH, NSB, NSMS and TSW) only without significant loss in
genetic gains. This will save resources and time of breeders
to compute seed yield. This is the first report on computation
of selection index for efficient simultaneous selection under
THS in Indian mustard.
Keywords: Brassica juncea, terminal heat stress, direct effects, indirect effects, yield traits
Year: 2020
Volume: 80
Issue: 1
Article DOI: 10.31742/IJGPB.80.1.13
Print ISSN: 0019-5200
Online ISSN: 0975-6906
Surinder K. Sandhu, Pritpal Singh, Jasneet Kaur, Manpreet Singh and Karanveer Kaur info_circle
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