| In order to make the yield further improved and make clear about the allocation dynamics of photosynthetic product between source and sink, we study the physiological characteristics of resource, sink, flow and their relationships. This paper take three different spike type cultivars in Guanzhong Area as materials, and studied the effects of Source-Sink change on the some physiological characters and dry matter accumulation and transfer in different spike-type wheat varieties at late growth stage. This study is to lay a foundation for wheat high-yield breeding and cultivation theoretically.The main results as follows:1. In big ear variety, bigger tassel and more grains are notable features, so yield of single plant is the highest, the main measures of harvesting higher wheat yield are more filling; In intermediate variety, grain wheat and effective spike rate of tiller all are medium, population yield is highest; In multiple ear variety, effective spike rate of tiller is highest, but the yield of single plant is lowest, so the population yield is lowest.Grains per spike, seed weight per 1000-kernel, grain weight and yield are all decreased after leaf removal. Yield of big ear wheat decreased little (T5 is 14.08%) , its decreased mostly in intermediate and multiple ear variety (T5 is 19.76%,20.60%) .2. The output functional periods of the top three leaves in big ear wheat is longer in intermediate and multiple ear variety when filling. The functional periods of top third leaf shortened when leaves removal; the output functional periods of leaves in every nod extend, especially in top second and third leaf.3. In the latter part of wheat's growth, descending speed of photosynthetic rate in large spike cultivar is lower significantly than that of inter-mediate ear type and multi-eared type in the same leaf positions. Photosynthesis in different leaf source has the ability of mutual compensation after the source-reducing. The compensation in the leaf in large spike cultivar is greater than that in the leaf of intermediate ear type and multi-eared type. Reduced ear causes the function decline of the leaf-source.4. The content of chlorophyll in flag leaf is lower at the front stage of grain filling for the large spike cultivar and the peak of that content come out latterly. But in the latter stage of the grain filling, the content of chlorophyll decline slowly and the content is higher than that of inter-mediate ear type and multi-eared type relatively.When do source-reducing on the various types of species, the chlorophyll content in flag leaf in the front stage of grain filling is higher than that of CK. The more are source-reducing, and closer to the ears, the content is higher. The chlorophyll content rapid decrease along with the growth, the more are source-reducing, and closer to the ears, the faster to decline. The increasing ranges of content of Chl and soluble sugar lager in big ear wheat than that of intermediate ear type and multi-eared type relatively. Further explain the compensation ability in the leaf of the large spike cultivar is greater than that in the leaf of intermediate ear wheat and multiple ear wheat. Chl content and soluble sugar content of flag leaf in cutting ears is higher than CK, decreased rapidly along with the growth, so the content is much larger than CK and other treatments at late growth stage.5. The filling of multiple ear wheat started earliest, while big ear wheat beginning latest. Content sequence of maximum growth rate and final grain weight are the same, they are: big ear wheat>medium ear wheat >multiple ear wheat. Cut the ear1/2, the maximal filling rate improved and the time to that period in all variety prolonged.6. In term of grouting speed of every period, big ear and intermediate ear varieties both showed: middle period > latter period > former period, while multiple ear variety showed middle period > former period > latter period. Compared with grouting speed, former period indicated: intermediate ear > multiple ear > big ear; middle and latter period: big ear> intermediate ear > multiple ear.The reduction of resource had light affect on the days of grouting of three varieties. But it obviously decreased the speed of grouting, and resource reduction more, the decrease larger. Big ear and intermediate ear varieties both declined more at the middle period of grouting, while multiple ear variety did more at the middle and latter period of grouting. The shrink of sink increased slightly the days of three grouting periods of three varieties and the speed of grouting.7.Soluble sugar content of seed of all treatments of each types varieties after anthesis showed downward trend, and the highest time is 12 days after anthesis, this of large-panicle type varieties decreased rapidly between 12and 30 days after anthesis, decreased slowly 30 days after anthesis.Starch content showed rising trend in filling stage, the increasing amount of starch content of large-panicle type varieties was always higher than intermediate ear varieties after anthesis. 8.Compared with the CK, the dry matter weight of both single plant and stem and sheath with reduce source treatment ,and the difference all reached significant level; difference of different treatment of the same type materials also reach significant level.the more to reduce source, the more the single plant weight reduces. The change of dry matter weight total accumulation between the resources treatment and the CK always showed that large panicle type> medium panicle type> multiple spike type.The change of dry matter in stem and sheath of large panicle type variety only T5,T6 are the same as the medium panicle type and multiple spike type, while the dry matter weight of the rest treatment reduce first and increase latter, and its amplitude reduction less than the intermediate and multiple spike type. .9. Decreased magnitude of grain weight per ear in big ear wheat (4.42%-22.11%) far less than intermediate(6.77%-35.42%)and multiple ear variety(7.26%-37.9%), some appropriate treatment will not produce remarkable influence to grain weight of big ear wheat.10. The contribution rate of storage substance in stem and sheath to grain in big ear variety is 9.0%, which is far lower than intermediate (20.41%) and multiple ear variety (17.69%). The contribution rate of storage substance in stem and sheath to grain greatly improved at leaf removal, and the more leaf removed, the more contribution rate improved. In big ear variety, the contribution rate of storage substance in stem and sheath to grain improved to 81.05%, it increases by 9 times compared with CK; In intermediate variety, the contribution rate of storage substance in stem and sheath to grain improved to93.68%, it increases by 4.6 times; In multiple ear variety, the contribution rate of storage substance in stem and sheath to grain improved to 93.36%, it increases by 5.4 times.
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