| The removal of ears did not result in any significant change in photosynthesis
rate of flag leaf when compared at an active grain development stage of
control plants. At later stages the flag leaf of de-eared plants retained
higher rate of photosynthesis. AUSTlN & EDRICH (1975) also found that ear
removal did not affect the rate of photosynthesis of the subtending flag
leaf. Their studies showed that a new pattern of translocation was established
within 2-3 days of ear removal. Similar explanation may be valid for the
present results in the sense that removal of MS ears increased the ear weight
of tillers. The removal of ears of MS and tillers caused a remarkable increase
in the shoot weight of tillers; suggesting the existence of alternative
sink capacity. The roots, which may be the important sink for assimilates
in de-eared plants and the weight of the ears at the time of their removal
were not included in this study. This might be the reason for less dry weight
of de-eared plants. The lower photosynthesis rate of flag leaf in control
plants compared to de-eared plants at a later stage could possibly be due
to a decrease in requirement of assimilates by the ear in control plants
as it was approaching maturity and development of alternative sink capacity
in de-eared plants. Acknowledgement This research has been financed in part by a grant made by the United States Department of Agriculture under the Cooperative Agricultural Research Program. References ASANA, R.D. 1968. Indian J. Plant Physiol. 11: 1-10. AUSTIN, R.B. and J. EDRICH. 1975. Ann. Bot. 39: 141-152. AZCON-BIETO, J. 1983. Plant Physiol. 73: 681-686. DANTUMA, G. 1973. Neth. J. Agric. Sci. 21: 181-187. GHILDIYAL, M.C. and G.S. SIROHI. 1986. Photosynthetica 20: 102-106. GIFFORD, R.M. and L.T. EVANS. 1981. Annu. Rev. Plant Physiol. 32: 485-509. HODANOVA, D. 1981. Biol. Plant. 23: 58-67. KERR, P.S., T.W. RUFTY and S.C. HUBER. 1985. Plant Physiol. 77: 275-280. KING, R.W., I.F. WARDLAW and L.T. EVANS. 1967. planta 77: 261-276. NEALES, T.F. and L.D. INCOLL. 1968. Bot. Rev. 34: 107-125. PALLAS, J.E., Y.B. SAMISH and C.M. WILLMER. 1974. Plant Physiol. 53: 907-911. PARKINSON, K.J.,W. DAY and J.E. LEACH. 1980. J. Exp. Bot. 31: 1441-1453. RAWSON, H.M., J.H. HINDMARSH, R.A. FISCHER and Y.M. STOCKMAN. 1983. Aust. J. Plant Physiol. 10: 503-514. UPMEYER, D.J. and H.R. KOLLER.1973. Plant Physiol. 51: 871-874. YOSHIDA, S. 1972. Annu. Rev. Plant Physiol 23: 437-464. |
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