, Volume 45, Issue 2, pp 254–258 | Cite as

Photosynthesis and plant growth response of transgenic Bt cotton (Gossypium hirsutum L.) hybrids under field condition

  • K. B. Hebbar
  • N. K. Perumal
  • B. M. Khadi


Field experiments were conducted under rain-fed conditions to study the growth and photosynthetic efficiency of transgenic Bt cotton hybrids during 2002–03 and 2003–04 seasons. Three Bt cotton hybrids (Bollgard 1) and their non-Bt (NBt) counterparts viz. MECH 12, MECH 162, and MECH 184 were grown along with a local hybrid NHH44. Growth parameters such as plant height, main-stem nodes, biomass accumulation, and physiological processes like stomatal conductance (g s), and rates of transpiration (E) and photosynthesis (P N) did not differ significantly between Bt and NBt hybrids up to 80 DAS (d after sowing). Squaring commenced at 50 DAS both in Bt and NBt. The loss of young fruiting forms by the entomological factors was three times less in Bt than NBt. As a consequence, Bt had more early formed bolls on the lower canopy which contributed to higher biomass and seed cotton yield. On the other hand, bolls distributed intermittently in NBt. Heavy boll load altered the growth and physiological processes, and as a result Bt had higher g s, E, and P N than NBt. Since developing bolls (sink) divert the saccharides and nutrients from other organs, Bt plants with heavy boll load senesced early and stopped the production of new squares and bolls. Thus, the boll load influenced the change in growth and physiological processes of Bt from NBt.

Additional key words

boll load dry matter Gossypium node number plant height senescence square and boll shedding stomatal conductance transpiration yield 


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  1. Bhatt, J.G., Ramanujam, T., Seshadrinathan, A.R.: An assessment of the loss of floral forms in cotton.-Indian J. agr. Sci. 42: 210–214, 1972.Google Scholar
  2. Dong, H.Z., Tang, W.J., Li, W., Li, Z.H., Zhang, D.M.: Effects of genotypes and plant density on yield, yield components and photosynthesis in Bt transgenic cotton.-J. Agron. Crop Sci. 192: 132–139, 2006.CrossRefGoogle Scholar
  3. Edson, C.E., Howell, G.S., Flore, J.A.: Influence of fruit load on photosynthesis and dry matter partitioning of Seyval grapevines. II. Seasonal changes in single leaf and whole vine photosynthesis.-Amer. J. Enol. Viticult. 46: 469–477, 1995.Google Scholar
  4. Foyer, C.H.: Feedback inhibition of photosynthesis through source-sink regulation in leaves.-Plant Physiol. Biochem. 26: 483–492, 1988.Google Scholar
  5. Godoy, A.S., Moreno, A.L.E., Garcia, C.E.A.: Plant growth analysis of transgenic Bt. cotton.-In: Proc. Beltwide Cotton Conf., San Diego 1988.Google Scholar
  6. Goldschmidt, E.E., Huber, S.C.: Regulation of photosynthesis by end-product accumulation in leaves of plants storing starch, sucrose and hexose sugars.-Plant Physiol. 99: 1443–1448, 1992.PubMedGoogle Scholar
  7. Guinn, G.: Fruiting of cotton. III. Nutritional stress and cutout.-Crop Sci. 25: 981–985, 1985.CrossRefGoogle Scholar
  8. Iglesias, D.J., Lliso, I., Tadeo, F.R., Talon, M.: Regulation of photosynthesis through source:sink imbalance in citrus is mediated by carbohydrate content in leaves.-Physiol. Plant. 116: 563–572, 2002.CrossRefGoogle Scholar
  9. Jasoni, R., Cothren, T., Fernandez, C.: Carbondioxide exchange rate of cotton after complete removal.-J. Cotton Sci. 4: 91–96, 2000.Google Scholar
  10. Layne, D.R., Flore, J.A.: End-product inhibition of photosynthesis in Prunus cerasus L. in response to whole-plant source-sink manipulation.-J. amer. Soc. hort. Sci. 120: 583–599, 1995.Google Scholar
  11. Martinez, C.R., Cervantes, E., Pérez, P., Morcuende, R., Martin del Molino, M.: Effect of sink size on photosynthesis and carbohydrate content of leaves of three spring wheat varieties.-Physiol. Plant. 89: 453–459, 1993.CrossRefGoogle Scholar
  12. Mohan, K.S., Manjunath, T.M.: Bt. Cotton — India’s first transgenic crop.-J. Plant Physiol. 29: 225–236, 2002.Google Scholar
  13. Naor, A., Gal, Y., Bravdo, B.: Crop load affects assimilation rate, stomatal conductance, stem water potential and water relations of field-grown Sauvignon blanc grapevines.-J. exp. Bot. 48: 1675–1680, 1997.Google Scholar
  14. Quaim, M., Zilbermann, D.: Yield effects of genetically modified crops in developing countries.-Science 299: 900–902, 2003.CrossRefGoogle Scholar
  15. Pettigrew, W.T., Heitholt, J.J., Meredith, W.R., Jr.: Early season floral bud removal and cotton growth, yield and fiber quality.-Agron. J. 84: 209–214, 1992.CrossRefGoogle Scholar
  16. Ramasundaram, P.: The performance of Bt cotton hybrids in India.-ICAC Recorder 23: 17–18, 2005.Google Scholar
  17. Sadras, V.O.: Compensatory growth in cotton after loss of reproductive organs.-Field Crops Res. 40: 1–18, 1995.CrossRefGoogle Scholar
  18. Sahai, S., Rahman, S.: Mahyco-Monsanto’s Bt cotton fails to perform.-Curr. Sci. 85: 426–427, 2003.Google Scholar
  19. Setter, T.L., Brun, W.A., Brenner, M.L.: Stomatal closure and photosynthetic inhibition in soybean leaves induced by petiole girdling and pod removal.-Plant Physiol. 65: 884–887, 1980.PubMedCrossRefGoogle Scholar
  20. Singh, J., Blaise, Rao, M.R.K., Mayee, C.D., Deshmukh, M.S.: Assessment of agronomic efficiency of Bt cotton in rainfed vertisol.-J. indian Soc. Cotton Improvement 28: 185–190, 2003.Google Scholar
  21. Wright, P.R.: Premature senescence of cotton (Gossypium hirsutum L.). Predominantly a potassium disorder caused by an imbalance of source and sink.-Plant Soil 211: 231–239, 2004.CrossRefGoogle Scholar
  22. Wünsche, J.N., Palmer, J.W., Greer, D.H.: Effects of crop load on fruiting and gas-exchange characteristics of ‘Braeburn’/M.26 apple trees at full canopy.-J. amer. Soc. hort. Sci. 125: 93–99, 2000.Google Scholar

Copyright information

© Institute of Experimental Botany, ASCR 2007

Authors and Affiliations

  1. 1.Central Institute for Cotton ResearchNagpurIndia

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