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Fresh wt. of flaf leaf
Fresh wt. per flag leaf was significantly lower in Mn
stressed plants except in KSML 3 (Table
6). The growth of flag leaf was not much depressed
except in DWL 5023 and WG 357. This implied that although
the deficiency symptoms were abundantly present on other
highly and moderately susceptible cultivars, the flag leaf
growth was not affected. Alternatively, at later growth
stage, the mobilization of Mn upwards increased following
sufficient root growth. In cultivars WL 1562 and WG 377, the
flag leaf wt. was highest although grain formation in these
cultivars was nil (WG 1562) or partially inhibited (small
triangular grains in WG 377). Thus photosynthesis of the
flag leaf did not appear to be the major contributing factor
for ultimate grain yield as advocated previously by Evans
and Dunstone (1970) and Jatimliansky et al. (1982).
Probably, the other limiting factors like lack/or imbalance
of growth regulators, infertility of pollen(stigma and) or
inviability of embryos might be responsible for this
effect.
Viability of seeds
The Table 6 shows that the
germination of seeds was not affected in Mn-deficient
plants, although the number of germinated seeds was less in
WL 711 and also in WG 377, but in the latter, the
ungerminated seeds were the underdeveloped half seed
structures. Thus there appeared to be no deficiency of
starch in the developing grain. The main processes that were
affected were the pollination and fertilization and not the
grain filling.
It can be concluded that triticale TL 419 and C 306 were Mn
efficient and thus could be grown on marginally deficient
soils. It remains to be established whether the mechanism of
enhanced Mn utilization is linked with the morphology of
root system in these cultivars.
References
ASANA, R. D. 1974. Grain development at different positions
on the ear of wheat. Ind. J. Genet. P1. Bred. 34:
971-979.
BREMNER, P. M. 1972. Accumulation of dry matter and nitrogen
by grain in different positions of wheat ear as influenced
by shading and defoliation. Aust.: Biol. Sci. 25:
657-668.
DUA, I. S. and BHARDWAJ, S. N. 1979. Influence of growth
regulating substances in grain growth in aestivum
wheats. Indian J. Plant Physiol. 22: 50-56.
JATIMLIANSKY, J-R.; BISMUTH, E. & CHAMPIGNY, M-L. 1982.
Role of photosynthesis of the flag leaf and the ear in grain
reserve development of wheat differing in genome
composition, ploidy level and degree of selection. Comptes
Rendus Hebdomandaires des Seances de l'Academie des
Sciencies, III, 295 (5), 407-412.
EVANS, L. T. and DUNSTONE, R. L. 1970. Some physiological
aspects of evolution in wheat. Aust. J. Biol. Sci. 23:
725-741.
WARDLAW, T. F. 1968. The control and pattern of movement of
carbohydrates in plants. Bot. Rev. 34: 79-97.
WAREING, P. F. 1979. Plant Development and Crop Yield: In
photosynthesis and Plant Development (Marcelle, R;
Clijsters, H and Van Poucke, M. Eds) p. 1-17.
WEGRZYN, V. A., HILL, R. R. Jr. and BAKER, D. E. 1980. Soil
fertility-Crop genotype associations and Interactions. Jour.
Plant Nutr. 2: 607-627.
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