Study On The Effects Of Different Photoperiod Treatment On Winter Wheat

A few of winter wheat at present were studied, which were potted plant, through treatment of different day light, to research their photoperiod sensitivity, spieled differentiation, formation of the number of the final leaves, the maturing development, earliness, plant height and spike traits et al. The results were as followed:1. The effect of spike differentiation as affected by changing photoperiod:(1) The experiment of the whole short day length and transferred long photoperiod at the beginning of the double ridges stage as well as the whole long day length: The photosensitive cultivars, during the whole spike differentiation process, were prohibited. The stage that from differentiation of glumes to floral differentiation was lest prohibited, the stage that appearance of double-ridge stage and stamen and pistil stage were most prohibited, but the stage that after stamen and pistil differentiation was less done. The photo insensitive cultivars, during the process, were most prohibited at the beginning of the double-ridge, stamen and pistil and heading stage, secondly prohibited from double-ridge to glumes differentiation, slightly prohibited from differentiation of glumes to floral differentiation stage.(2) The experiment of the plants transferred from long to short day length:Firstly, with the transferring days delayed, the prohibiting effect reduced. The non-photo insensitive cultivars were less affected than the photosensitive ones. Secondly, the delaying effect of short day length had certain characteristic of "lag response time".2. The genotypic variation of final leaf number of wheat as affected by changing photoperiod:If the plants were treated with long day length until double-ridge stage, the final leaf number was stable and remained unchanged. The differentiated primordial was not affected by changing photoperiod thereafter; If the plants were always treated with short day length before double-ridge stage, some of the differentiated primordial at the base of young spikes at double ridges stage might be uncertain, they would develop into leaves under short day length or into spike lets under long day length.3. The phases development of wheat as affected by changing photoperiod: The phasic development of wheat was prohibited under the short day length. The photosensitive cultivars, from joining time to flagging time and from heading time to flowering time, was most prohibited, from getting up time to joining time was less done. For photo insensitive cultivars, all the phasic development were sanely prohibited, but which were different from photosensitive cultivars, from heading time to flowering time, under the long day length treatment, the development became longer than that of the short day length treatment.4. The effect of different day length on spikes characteristics of winter wheat:(1) The photosensitive cultivars were more responsible to photoperiod and the number of spike lets and the length of spike lets were more controllable than that of the photo insensitive cultivars.(2) The number of total seeds per spike was increased under treatment of shot day length, while decreased under treatment of long day length.(3) Long day length increased the 1000-kernel weight, while short day length decreased it.