| The increased output of wheat is the result of interaction between variety potential and environmental impacts, and the Variety Potential is the leading factor. There are 3 high - yield models in wheat production: the use of multiple-ear varieties for increasing the effective spikes of unit-acreage, the use of big-ear varieties for increasing the grain number and grain weight, and also the use of mediate varieties for the coordinative increase of effective spikes, grain number and grain weight. As the yield is a very complex character, all the yield factors may have some negatively correlation with each other, so to extrude one factor's role will not always give high yield. But currently, the high yield population of some multiple-ear varieties and some mediate varieties has or nearly reached their saturated state, it is easily to cause population lodging. Recently, many scholars have found that the high yield variety's construction has changed from multiple-ear varieties to mediate varieties, and then to big-ear varieties when the investment of water-fertilizer and the grain unit yield increased. However, the big-ear variety has 3 fatal disadvantages: late - maturing, poor gain filling and low ear-bearing tiller. To these existing problems, we have breaded a new big-ear variety--Xinong9814, which is semi-winter , premature and good grain filling, its 1000 grain weight has reached about 50g. Though it has overcome many disadvantages, it still has some disadvantages, take low ear-bearing tiller for example. To quickening the production application and the super high yield utilization of Xinong9814, this paper made some research as follow:1. By many times'following-observation on spike differentiation, we found the poor synchrony of main stem and later tiller, means too high main stem superiority, is the main reason of Xinong9814's low ear-bearing tiller. The later tillers' degradation happened at reviving stage: The first grade tiller degraded at formation of pistil and stamen primordium stage, the leaf age was 4 leaves to core and 5 leaves; The second grade tiller degraded at glume differentiation stage, the leaf age was core and 3 leaves to 4 leaves. To compensate the defects brought by low ear-bearing tiller, we used the measures of increasing seeding rate, which lead 1000 grain weight and grain number per ear decreased slightly, but ears per mu increased significantly. By increasing seeding rate, Xinong9814's ears per mu can reach 340,000 easiely, and the actual output of Xinong9814 is 736.5kg/667m2, so Xinong9814can easily realize the super high yield level with no doubt, and it can be used in the Field if by means of increasing seeding rate.2. Comparison of different varieties' Source and Sink, the results suggest: As a whole group, the relation of Xinong9814's Source and Sink is disharmony, the Source is insufficient. The low ear-bearing tiller is the fundamental cause of this disharmony relation in group.3. Xinong9718 is the best parent for Xinong9814's improvement, and its possibility to make Xinong9814 to be a 'small leaf & big - multiple ear' wheat variety is rather high. When making selection of fine individual from the hybridization combination of Xinong9718 & Xinong9814, these characters can be selected at early generation: flag leaf length, flag leaf width, flag leaf area, single grain weight, 1000 grain weight, grain number per ear and spikelet number. But these characters, flag leaf bend degree, plant loose degree, maximum tiller number, ears per plant and percentage of ear bearing tiller, should be selected unstrictly at early generation, but strictly at advanced generation.
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