All Title Author
Keywords Abstract

Pollination dynamics, grain weight and grain cell number within the inflorescence and spikelet in oat and wheat

DOI: 10.4236/as.2011.23037, PP. 283-290

Keywords: Cell Number, Distal Grain, Filling Potential, Floret, Oat, Pollination, Primary Grain, Proximal Grain, Secondary Grain, Wheat Cell-PLoc, Signal-CF, Signal-3L

Full-Text   Cite this paper   Add to My Lib


Oat (Avena sativa L.) and wheat (Triticum aestivum L.) vary in the structure of their inflores-cences and also in how pollination proceeds within the inflorescence. In both species the grain position in the spikelet determines grain weight potential. Primary grains in oat and proximal grains in wheat weigh more than secondary and distal grains. This variation in grain weight can potentially result from differences in post-pollination cell division in the grain. In this study pollination duration and dynamics were analyzed from head samples collected at two-day intervals, starting from the pollination of the most advanced floret. The number of grain cells was determined for individual grains throughout the inflorescence, starting from the pollination event. When mature, grain position in the spikelet and spike was noted and grain weight assessed. Pollination advance in oat proceeded from the uppermost primary floret towards the basal spikelets in ten to eleven days. Within the spikelet, the primary floret was pollinated on average one day earlier than the secondary floret. In wheat, pollination duration was four to five days, starting from the proximal florets in the mid-section of the inflorescence progressing towards the apical and basal spikelets. Proximal florets were pollinated one to two days earlier than distal florets. Maximum cell number in primary grains exceeded that of secondary grains in two oat cultivars. Similarly, primary grains were heavier than secondary grains. Cell number and single grain weight were correlated in terms of grain position in the spikelet (primary – secondary) and cultivar. Oat cultivar Belinda had a higher single grain weight than Fiia, which was also expressed as larger grain cell number. In wheat, proximal grains had higher maximum cell numbers and were also heavier than distal grains. This grain weight gradient was apparent throughout the inflorescence. Consequently, grain cell number is one of the possible regulators of grain-filling capacity in both cereal crops.


[1]  ?fors, M., Ohlander, L. and Stendahl, F. (1988). Str?s?dens utveckling I. En literaturstudie och beskrivning av en skala f?r best?mning av str?s?dens ax-respek- tive vippanlag. Sveriges Lantbruksuniversitet. Institution f?r v?xtodlingsl?r?. Uppsala. 75 p.
[2]  Peltonen-Sainio, P. and Pekkala, T. (1993). Numeric codes for developmental stages of oat apex in the growing conditions of southern Finland. Agricultural Science in Finland, 2, 329-336.
[3]  Rajala, A. and Peltonen-Sainio, P. (2004). Intra-plant variation in progress of cell division in developing oat grains: a preliminary study. Research note. Agricultural and Food Science, 13, 163-169.
[4]  Rawson, H. M. and Evans, L. T. (1970). The pattern of grain growth within the ear of wheat. Australian Journal of Biological Science, 23, 753-764.
[5]  Evans, L. T., Bingham, J. and Roskams, M. A. (1982). The pattern of grain set within ears of wheat. Australian Journal of Biological Science, 25, 1-8.
[6]  Bonnett, O. T. (1961). The oat plant: Its histology and development. Bulletin 672. University of Illinois. Agricultural Experiment Station. 112 p.
[7]  Peltonen-Sainio, P. and Peltonen, J. (1995). Floret set and abortion in oat and wheat under high and low nitrogen regimes. European Journal of Agronomy, 4, 253-262.
[8]  Langseth, W. and Rundberget, T. (1999). The occurrence of HT-2 toxin and other trichothecens in Norwegian cereals. Mycopathologia, 147, 157-165.
[9]  Youngs,V. L. and Shands, H. L. (1974). Variation in oat kernel characteristics within the panicle. Crop Science, 14, 578-580.
[10]  Housley, T. L. and Peterson, D. M. (1982). Oat stem vascular size in relation to kernel number and weight. I. Controlled environment. Crop Science, 22, 259-263.
[11]  Tibelius, A. and Klinck, H. R. (1987). Effects of artificial reduction in panicle size on weight of secondary seeds in oats (Avena sativa L.). Canadian Journal of Plant Science, 67, 621-628.
[12]  Crampton, M. W., Moot, D. J. and Martin, R. J. 1997. Kernel weight distribution within oat (Avena sativa L.) panicles. Proceedings Agronomy Society of New Zealand, 27, 83-87.
[13]  Doehlert, D. C., McMullen, M. S. and Riveland, N. R. (2002). Sources of variation in oat kernel size. Cereal Chemistry, 79, 528-534.
[14]  Miralles, D. J. and Slafer, G. A. (1995). Individual grain weight responses to genetic reduction in culm length in wheat as affected by source-sink manipulations. Field Crops Research, 43, 55-66.
[15]  Stoddard, F. L. (1999). Variation in grain mass, grain nitrogen, and starch B-granule content within wheat heads. Cereal Chemistry, 76, 139-144.
[16]  Duggan, B. L. and Fowler, D. B. (2006). Yield structure and kernel potential of winter wheat on the Canadian prairies. Crop Science, 46, 1479-1487.
[17]  Rajala, A., Hakala, K., M?kel?, P., Muurinen, S. and Peltonen-Sainio, P. (2009). Spring wheat response to timing of water deficit through sink and grain filling capacity. Field Crops Research, 114, 263-271.
[18]  Simmons, S. R. and Moss, D. N. (1978). Nitrogen and dry matter accumulation by kernels formed at specific florets in spikelets of spring wheat. Crop Science, 18, 139-143.
[19]  Calderini, D. F. and Ortiz-Monasterio, I. (2003). Grain position affects grain macronutrient and micronutrient concentrations in wheat. Crop Science, 43, 141-151.
[20]  Radley, M. (1978). Factors affecting grain enlargement in wheat. Journal of Experimental Botany, 29, 919-934.
[21]  Ma, Y-Z., MacKown, C. T. and Van Sanford, D. A. (1996). Differential effects of partial spikelet removal and defoliation on kernel growth and assimilate partitioning among wheat cultivars. Field Crops Research, 47, 201-209.
[22]  Cartelle, J., Pedró, A., Savin, R. and Slafer, G.A. (2006). Grain weight responses to post-anthesis spikelet-trim- ming in an old and modern wheat under Mediterranean conditions. European Journal of Agronomy, 25, 365-371.
[23]  Hanif, M. and Langer, R. H. M. (1972). The vascular system of spikelet in wheat (Triticum aestivum). Annals of Botany, 36, 721-727.
[24]  Egli, D. B. (2006). The role of seed in the determination of yield in grain crops. Australian Journal of Agricultural Research, 57, 1237-1247
[25]  Brocklehurst, P. A. (1977). Factors controlling grain weight in wheat. Nature, 266, 348-349.
[26]  Calderini, D. F., Abeledo, L. G., Savin, R. and Slafer, G. A. (1999). Effect of temperature and carpel size during pre-anthesis on potential grain weight in wheat. Journal of Agricultural Science in Cambridge, 132, 453-459
[27]  Calderini, D. F. and Reynolds, M. P. (2000). Changes in grain weight as a consequence of de-graining treatments at pre- and post-anthesis in synthetic hexaploid lines of wheat (Triticum durum x T. tauschii). Australian Journal of Plant Physiology, 27, 183-191.
[28]  Waddington, S. R., Cartwright, P. M. and Wall, P. C. (1983). A quantitative scale of spike initiation and pistil development in barley and wheat. Annals of Botany, 51, 119-130.
[29]  Tuberosa, R., Sanguineti, M. C., Stefanelli, S. and Quarrie, S. (1992). Number of endosperm cells and endosperm abscisic acid content in relation to kernel weight in four barley genotypes. European Journal of Agronomy, 1, 125-132.
[30]  Craufurd, P.Q. and Cartwright, P. (1989). Effect of photoperiod and chlormequat on apical development and growth I a spring wheat (Triticum aestivum) cultivar. Annals of Botany, 63, 515-525.
[31]  Peltonen-Sainio, P. and Rajala, A. (2007). Duration of vegetative and generative development phases in oat cultivars released since 1921. Field Crops Research, 101, 72-79.
[32]  Koch, H-J., Pringas, C. and Maerlaender, B. (2006). Evaluation of environmental and management effects on Fusarium head blight infection and deoxynivalenol concentration in the grain of winter wheat. European Journal of Agronomy, 24, 357-366.
[33]  Singh, B. K. and Jenner, C. F. (1982). Association between concentrations of organic nutrients in the grain, endosperm cell number and grain dry weight within the ear of wheat. Australian Journal of Plant Physiology, 9, 83-95.
[34]  Chojecki, A. J. S., Bayliss, M. W. and Gale, M. D. (1986). Cell production and DNA accumulation in the wheat endosperm and their association with grain weight. Annals of Botany, 58, 809-817.
[35]  Gao, X., Francis, D., Ormrod, J. C. and Bennett, M. D. (1992). Changes in cell number and cell division activity during endosperm development in allohexaploid wheat, Triticum aestivum L. Journal of Experimental Botany, 43, 1603-1609.
[36]  Myers, P., Setter, T., Madison, J. and Thompson, J. (1990). Abscisic acid inhibition of endosperm cell division in cultured maize kernels. Plant Physiology, 94, 1330-1336.
[37]  Ober, E., Setter, T., Madison, J., Thompson, J. and Shapiro, P. (1991). Influence of water deficit on maize endosperm development. Enzyme activities and RNA transcripts of starch and zein synthesis, cell division and ABA. Plant Physiology, 97, 154-164.
[38]  Barr?co, R. M., Peres, A., Droual, A-M., De Veylder, L., Ngyen, L. S. L., Wolf, J. D., Mironov, V., Peerbolte, R., Beemster, G. T. S., InzéD., Broekaert, W. F. and Frankard, V. (2006). The cyclin-dependent kinase inhibitor Orysa; KRP1 Plays an important role in seed development of rice. Plant Physiology, 142, 1053-1064.
[39]  Cochrane, M. P. and Duffus, C. M. (1983). Endosperm cell number in cultivars of barley differeing in grain weight. Annals of Applied Biology, 102, 177-181.
[40]  Peltonen-Sainio, P., Kangas, A., Salo, Y. and Jauhiainen, L. (2007). Grain number dominates grain weight in cereal yield determination: evidence basing on 30 years’ multi-location trials. Field Crops Research, 100, 179- 188.
[41]  Sadras, V. O. (2007). Evolutionary aspects of the trade- off between seed size and number in crops. Field Crops Research, 100, 125-138.
[42]  Michael, G. and Beringer, H. (1980). The role of hormones in yield formation. In: Physiological aspects of crop productivity. Proceedings of 15th IPI-Collection. International Potash Institute. Pp. 85-115. Der Bund, Bern.
[43]  Mounler, M., Bangerth, F. and Story, V. (1980). Gibberellin-like substances and indole type auxins in developing grains of normal and high-lysine genotypes of barley. Physiologia Plantarum, 48, 568-573.
[44]  Yang, J., Zhang, J., Huang, Z., Wang, Z., Zhu, Q. and Liu, L. (2002). Correlation of cytokinin levels in the endosperms and roots with cell number and cell division activity during endosperm development in rice. Annals of Botany, 90, 369-377.
[45]  Xu, G., Zhang, J., Lam, H.M., Wang, Z. and Yang, J. (2007). Hormonal changes are related to the poor grain filling in the inferior spikelets of rice cultivated under non-flooded and mulched condition. Field Crops Research, 101, 53-61.
[46]  Yang, J., Zhang, J., Wang, Z., Liu, K. and Wang, P. (2006). Post-anthesis development of inferior and superior spikelets in rice relation to abscisic acid and ethylene. Journal of Experimental Botany, 57, 149-160.
[47]  Nicolas, M. E., Gleadow, R. M. and Dalling, M. J. (1985). Effect of post-anthesis drought on cell division and starch accumulation in developing wheat grains. Annals of Botany, 55, 433-444.


comments powered by Disqus