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Triticeae Genomics and Genetics 2014, Vol.5, No.2, 1-11
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Research Report Open Access
Evaluation of Some Wheat Hybrids under Normal and Heat Stress Conditions
Jehanzeb Farooq
1
, Ihsan Khaliq
2
, Abid Mahmood
3
1. Cotton Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan
2. Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan
3. Director General Agri. Research Ayub Agricultural Research Institute, Faisalabad, Pakistan
Corresponding author email:
jehanzeb1763@hotmail.com
Triticeae Genomics and Genetics, 2014, Vol.5, No.2 doi: 10.5376/tgg.2014.05.0002
Received: 30 Nov., 2014
Accepted: 30 Dec., 2014
Published: 31 Dec., 2014
Copyright
©
2014 Farooq and Khaliq, This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Farooq and Khaliq, 2014, Evaluation of Some Wheat Hybrids under Normal and Heat Stress Conditions, Triticeae Genomics and Genetics, Vol.5, No.2 1
-
11
(doi:
10.5376/tgg.2014.05.0002
)
Abstract
Heat shocks at anthesis are one of the major limitations in wheat productivity in many countries worldwide including
Pakistan. Present investigations were designed to battle out this calamity which may further be exploited in breeding heat tolerant
cultivars. Seven parents including tolerant, moderately tolerant and susceptible but high yielders were utilized for this purpose and
later hybridized in a 7 ×7 diallel fashion. Analysis of variance revealed significant variability for all the parameters studied. Highest
value of negative and desirable significant heterosis and heterobeltiosis for plant height was shown by the cross combinations
Weebli-1 × Uqab-2000, Inqilab-91 × Shalimar-88 under normal conditions and under stress by the hybrids Uqab-2000×Weebli-1,
Shalimar-88 × Maya/Pavon. Maximum positive heterosis for tillers per plant was recorded by the cross combination
Shalimar-88×Chenab-2000 (12.04%) and maximum positive and highly significant heterobeltiosis was recorded by the cross
combination Shalimar-88 × Chenab-2000 (11.46%). Under stress for tillers per plant none of the crosses showed positive estimates.
Maximum positive heterosis for 100- grain weight was shown by the cross combination Chenab-2000 × Inqilab-91 (28.22%).
Maximum positive heterosis under stress for 100-grain weight was shown by the cross Inqilab-91×Weebli-1 (23.35%) followed by
Chenab-2000 × Inqilab-91 (22.22%). Maximum positive heterosis for grain yield under normal conditions was manifested by the
cross combinations Uqab-2000×Punjab-85 (28.70%) and under stress maximum positive heterosis was recorded by cross
combination Shalimar-88 × Uqab-2000 (27.02%). The results of heterosis and heterobeltiosis estimation revealed that the hybrid
vigor is available in the current experiment for all the traits and selection of desirable hybrids is the best way to improve the grain
yield of bread wheat. Many cross combinations in the current studies may be utilized following pedigree or bulk method to develop
heat tolerant wheat varieties because of their ability to perform well under normal and heat stress conditions.
Keywords
Terminal heat stress; Heterosis; Bread wheat; Cereals; Pakistan
Background
Bread Wheat is among the leading cereals grown in
Pakistan and all over the world. Its cultivation is most
suitable in areas with cool environmental conditions
(Farooq et al., 2013; Modhej et al., 2008). Its trend of
cultivation is rising in areas that are too warm for
favorable production (Farooq et al., 2011). Terminal
heat stress in many areas of the world in the recent
past resulted in poor grain filling, which is the most
decisive stage of grain development. A little heat
stress (≥35°C) during this point reduces starch
contents ultimately decreasing grain quality and
weight (Sial et al., 2005).
For the development of new varieties having desirable
traits choice of parents is the most important step.
Utilization of heterotic effects for grain yield was
mostly related to cross pollinated crops. In wheat
hybrid vigour is directly related to the effective
selection of the parents. But results of different
researchers on hybrid vigour do not show such
parallelism. According to the findings of Cox &
Murphy (1990) and Picard et al., (1992) prospect of
developing superior genotype is more if both parents
used in crosses have parallel performance instead of
one parent being lesser or greater in terms of one or
more traits. However, genetic variation between
parents is vital to develop superior hybrids (Morgan,
1998; Fabrizius et al., 1998; Baric et al., 2004). The
parents with better yielding potential show less
heterosis for yield because parents already have many
valuable genes in homozygous state Morgan et al.,