|
|
|
Authors: Vinay Mahajan1
, N V P R G Rao1, S K Sethi2, N S Bains3, G S
Nanda3 and S Nagarajan1 Corresponding
author: Email: vimahan@hotmail.com Addresses: 1Directorate
of Wheat Research, P O Box 158, Karnal 132 001, India; Contents
|
| Abstract | Key words | Introduction |
| Materials and Methods | Results
and Discussion |
Literature
Cited |
Spring wheat is an important crop of winter season and widely grown in northern parts of the Indian sub-continent. Nineteen single cross wheat hybrids along with checks namely, PBW343 and HD2687 were evaluated at Karnal, Ludhiana and Hisar on ridge planting in randomized block design. Hybrid-environment interaction was significant for yield. All the hybrids under evaluation exhibited significant deviation for regression for yield. Standard heterosis above 14 per cent was observed in HM 99495 and HM 00504 at Karnal center, however these were unstable over other environments under test.
Key words:
Bread wheat, Chemical Hybridizing Agent, Hybrids, Regression, Stability and
Yield,
Wheat
(Triticum aestivum) is the second most
important crop after rice in India. The North-Western Plains Zone (NWPZ) that
constitute Punjab, Haryana, north Rajasthan and western UP is known as bread
bowl of India. The yield gains in this region exhibit about 1% per year. To
achieve the production projections of 109mt by 2020AD of wheat in India the new
innovative methods like exploitation of heterosis through hybrid wheat could be
a plausible alternative. The hybrid wheat is targeted for irrigated, high
fertility, timely sown conditions of NWPZ.
Enough
reports are available in literature indicating high heterosis over mid-parent or
the best parent however the real commercial feasibility of hybrid wheat depends
upon the heterotic advantage over the best ruling variety of that agro-climatic
zone. Globally the scientists dealing with various aspects of hybrid wheat found
that the standard heterosis for grain yield on bigger plot basis as compiled by
Mahajan et al (1999) ranged from 6% (Borghi et
al 1988) to as high as 41% (Zehr et al
1997). The aim of the present investigation was to study the stability of
the wheat hybrids over locations in North-Western Plains Zone of India for
important characters like yield and related components as well as to understand
the heterosis for yield at different locations.
Nineteen bread wheat hybrids produced through chemical hybridizing agent (CHA) at Directorate of Wheat Research, Karnal (14), Punjab Agricultural University, Ludhiana (3) and Haryana Agricultural University, Hisar (1) were evaluated at Karnal, Ludhiana and Hisar locations of North Western Plains Zone of India during rabi 2000-01. These hybrids were grown in three replications in randomized block design at each location in a plot of 8.4 sq m on ridge planting using “Raised bed Fixed Plot Drill” (Mahajan and Nagarajan, 2001) between 1st to 15th Nov. 2000. The genotypes were grown in paired rows on each ridge. The distance between rows was 0.15m on each ridge while distance between plants was 0.02m. The hybrids were evaluated at a seed rate of 50 kg/ha while the popular check varieties PBW343 and HD2687 were grown both at 50 kg/ha and 100 kg/ha (normal seed rate in practice).
Data was recorded for plot yield (g), tillers/meter ridge, grains/ spike, thousand-grain weight (g), plant height (cm), days to 50% heading and maturity. Five competitive plants from each plot were randomly taken for recording observations on grains/ spike and plant height. The observation on days to 50% heading and maturity were taken on plot basis. The data was computed for stability analysis following Eberhart and Russell (1966) and standard heterosis for hybrids were computed at each location over the best check following Meredith and Bridge (1972).
The
results indicated that the hybrid-environment (HE) interaction was significant
for only yield while for other characters HE-interaction was not significant (Table1).
Hence, the data of yield was used to study the stability of hybrids over three
locations viz. Karnal, Hisar and Ludhiana. On partitioning the HE-interaction
for yield it was observed that the Hybrid x Env. (linear) interaction was not
significant indicating that the environments did not differ significantly (Table
2).
Highly
significant pooled deviation for yield indicate that the performance of hybrids
differ over environments. Wheat hybrids are found to be stable for their
performance in different environments and seasons as observed by Wienhues (1968)
and Stroike (1987), while Boland and Walcott (1985) and Borghi and Perenzin
(1990) reported that the yield stability of the hybrids was intermediate to that
of the parents. In contrast, our experiments indicated highly deviation from
regression for all the hybrids as well as checks (Table
3).
The
standard heterosis over the best check at each location indicated that the
yields of hybrids were generally very low at Ludhiana center. Therefore the
overall performance of hybrids at Ludhiana may be adding to the unstable
performance of hybrids over locations. Fabrizino and co-workers (1998) are of
the view that the expression of heterosis was due in part to genetic diversity
but was unpredictable and also depended on factors not elucidated by their
study.
Scientists have reported varying degree of yield heterosis in wheat (Edwards et. al. 1980 and Perenzin and Borghi 1987) and have suggested the production of hybrids to exploit the non additive type of gene action involved in the expression of grain yield to break the existing yield plateau in this crop. The computation of standard heterosis for Karnal and Hisar indicated that seven and one hybrids respectively, were superior to the best check. Among them HM 99495 and HM 00504 were exhibiting above 14% standard heterosis at Karnal and hold promise (Table 4). Hence in order to identify hybrids with high yield and stable performance it is important to continue to churn out more adaptable germplasm in hybrid wheat programme.
The authors are grateful to the research associates in working in A P CEES fund project. The authors duly acknowledge the financial assistance from A P CESS fund project “Development of Hybrid Wheat”.
Boland, O.W. and
J.J. Walcott. 1985. Levels of heterosis for yield and quality in an F1 hybrid
wheat. Australian Journal of Agricultural
Research. 36: 545-552.
Borghi, B. and M.
Perenzin 1990. Yield and yield stability of conventional varieties and F1 bread
wheat hybrids. Journal of Genetics and
Breeding 44: 307-310.
Borghi, B., M.
Perenzin and R.J. Nash. 1988. Agronomic and qualitative characteristics of ten
bread wheat hybrids produced using a chemical hybridizing agent. Euphytica 39: 185-194.
Eberhart, S.A.
and W.A. Russell 1966. Stability parameters for comparing varieties. Crop
Sciences 6: 36-40.
Edward, I.B., W.G.
Thomson and D.W. Pingree. 1980. Pioneer Hi-Bred International, Inc.; Department
of Cereal Breeding Report. Annual Wheat
Newsletter 26: 36-37.
Fabriozino, M.A.,
R.H. Busch, K. Khan and L. Huckle 1998. Genetic diversity and heterosis of
spring wheat crosses. Crop Science 38(4):
1108-1112.
Mahajan, V. and
Nagarajan S. 2001 Hybrid wheat evaluation by raised bed fixed plot drill. ICAR
News (A Science and Technology Newsletter) 7 (2): 19.
Mahajan,
V., Nagarajan S, Srivastav M, Kumar V and Ganga Rao N V P R 1999. Commercial
heterosis in wheat – an overview. Rachis 18(2): 13-16.
Meredith
W R and Bridge R R 1972. Heterosis and gene action in cotton Gossypium hirusutum.
Crop Science 12: 304-310.
Perenzin, M. and
B. Borghi. 1987. La produttivita degli ibridi di frumento tenero. Rivista di Agronomica 21 (4, Suppl.): 155-159.
Stroike, J.E.
1987. Technical and economic aspects of hybrid wheat seed production. In: Hybrid seed production of selected cereals, oil and vegetable crops.
pp. 177-185. FAO Plant Protection and Production paper 82, Food and Agriculture
Organization of the United Nations, Rome.
Wienhues, F. 1968. Long term yield analysis of heterosis in wheat and barley: variability of heterosis, fixation of heterosis. Euphytica 17: 49-62.
Zehr, B.E., V.P. Ratnalikar, L.M.M. Reddy and L.V. Pandey. 1997. Strategies for utilizing heterosis in Wheat, Rice and Oilseed Brassica in India pp. 232-233 (Abstr B28) In: The Genetics and Exploitation of heterosis in crops, 17-22 Aug 1997, Mexico city, Mexico.