Legume Genomics and Genetics 2016, Vol.7, No.1, 1-11
6
comparatively lower than other genotypes due to
efficient accumulation of photosynthesis in seeds
during grain filling at higher temperature. Though a
few days of exposure to high temperatures (30–35 °C)
during seed filling accelerates senescence, diminish
seed set and seed weight, and reduce yield in pluses
(Siddique et al., 1999), different genotypes within a
species have different capabilities in coping with the
heat stress (Wahid et al., 2007).
High temperature leads pollen sterility (Saini et al.,
1984) and hence seed yield depends on the
temperature during pollen development (Ploeg Van
der and Heuvelink, 2005). In the present study, high
pollen viability (60-70%) was observed for two heat
tolerant genotypes (FLIP2009-55L and IG2507) and
showed highly positive correlation with number of
pods per plant. Our results suggest that pollen viability
test could be used in laboratory for identification of
heat tolerant genotypes in lentil. The impact of heat
stress on pollen viability has already been
demonstrated in several legume crops including
chickpea, common bean, groundnut, and soybean
(Prasad et al., 1999; Porch and Jahn, 2001;
Devasirvatham et al., 2012; Djanaguirama et al.,
2013).
4 Conclusion
The present investigation shows that heat stress
significantly affects number of flowers, pods, and
seeds. Therefore, filled and unfilled pods on a single
plant basis and on the terminal branch are important
traits for phenotyping heat tolerance under field
conditions. Further, the pollen viability is a useful trait
for identification of heat tolerant genotype in lentil.
Our results clearly demonstrated that significant
genetic variability exits for these morphological traits
in cultivated gene-pool of lentil. These genotypes can
be considered as potential genetic resources to be used
in lentil breeding program for the development of heat
tolerant cultivars.
5 Materials and Methods
5.1 Plant materials
The present study included 334 lentil genotypes
representing local and exotic germplasm originating
from drought-prone areas, elite breeding lines from
national and international programs and improved
cultivars released in India. Breeding lines used in this
study were developed at the Indian Institute of Pulses
Research (IIPR), Kanpur, India. These lines are
derived from crosses involving parents adapted to
terminal heat-prone environments. These accessions
were evaluated in 2011-12 and 160 accessions (out of
above 334 accessions) that faced high temperature
(>35 ºC) during reproductive stage were again
screened for heat tolerance in 2012-13 (Table 4).
Table 4 Description of pedigree/collection number and
collecting/breeding organization of 160 lentil accessions used
over two years (2011-12 and 2012-13) in the present study
S.No
Accessi
on
Pedigree/Collect
ion Number
Collecting/
Breeding
organization
1
IG
2500
PANT-L 538
GBPUAT,
Pantnagar
2
IG
2506
PANT-L 643
GBPUAT,
Pantnagar
3
IG
2507
LL 3
PAU,
Ludhiana,
Punjab
4
IG
2508
LL 5
PAU,
Ludhiana,
Punjab
5
IG
2510
LL 25
PAU,
Ludhiana,
Punjab
6
IG
2519
PUSA 9
IARI New Delhi
7
IG
2525
T 31
IARI-RS, Kanpur
8
IG
2542
L 543
unknown
9
IG
2543
L 546
unknown
10
IG
2576
L 771
unknown
11
IG
2580
L 1278
unknown
12
IG
2588
LWS 1
JNKVV, Jabalpur,
UP
13
IG
2589
LWS 2
JNKVV, Jabalpur,
UP
14
IG
2593
LWS 6
JNKVV, Jabalpur,
UP
15
IG
2796
P 287
USDA,-RPIP, New
Delhi
16
IG
2797
P 290
USDA,-RPIP, New
Delhi
17
IG
2802
P 300
USDA,-RPIP, New
Delhi
18
IG
2817
P 326
USDA,-RPIP, New
Delhi
