Research On Starch Accumulation Rule In Different Growth Stage Of Japonica Rice In Cold Region

Heilongjiang Province is one of the important commodity grain producing area, is also animportant commodity grain production base in China. Rice production can meet China’s japonica ricemarket, and the world japonica rice market demand and have strategic importance. However thenortheast of china is a high risk region of low temperature damage and Heilongjiang Province as anmain planting area for north japonica rice in cold rigion, low temperature harming rice yelid and qualityseriously. In this thesis, Tengxi138, Wuyoudao No.1, Dongnong423, Dongnong425,Dongnong427and Songjing6was used as experimental material, and use low temperture water stress in tilleringstage, booting stage and filling stage of rice grown key period. study the functional leaf chlorophyllcontent, tiller dynamic and yeild of rice.Clear and definite the change rule of starch and starchcomponents accumulating regularity, microstructure of starch and paste traits of starch. announce theregulation effect of ADPG pyrophosphorylase and starch branching enzyme for starch. Providetheoretical basis for the research on cold tolerance of rice in Heilongjiang Province. The mainconclusions of this experiment are as follows:1.Chilling stress delay the happening of tillers, decline the tillering-Increase-rate,tillering-decrement-rate and the number of productive ear, increase productive tiller percentage.Dongnong423is the most sensitive to chilling stress.And the Dongnong425is the most insensitive tochilling stress.2.The performance of Chlorophyll content in different growth period with low temperature stress isdifferent: the content trending downwards after chilling stress at tillering stage, and at booting stage thedownward trend was more significant after chilling stress. The content of Chlorophyll in filling stage islower speed is faster after chilling stress. The performance of Chlorophyll content in different growthperiod after low temperature stress is different: when chilling stress was relieved at tillering stage,thecontent recovered quickly. And at booting stage the content was Slowly rising. At filling stage thecontent sustained downward trend.Different varieties under chilling stress has different performance,dongnong423is most sensitivein tillering stage and booting stage. Effect of Songjing6after chilling stress in tillering stage andbooting stage is small, and influence large in filling stage. Dongnong427shows more stable underchilling stress.3.Chilling stress impedes the synthesis of starch at filling stage, but there is no significant influenceat tillering and booting stage. The impect of Chilling stress at filling stage include: chilling stress hurt the ADPG pyrophosphorylase and Q enzyme’s directly cause enzyme activity ruduced; dicreased thecontent of starch in rice grain, the chilling stress is most important to failure of microstructure of ricegrain, the amyloplasts loose arrangement and becomes more microporous, the amyloplasts was easlybreak led to the starch granule bared, the HPV, CPV, CSV, SBV of RVA profile was significantly rose,and the PKV, BDV have dropped significantly, this process ultimately results in inferior grain quality.The most sensitive varitives under chilling stress at filling stage is Songjing6and Tengxi138, andDongnong427is insensitive.4.The chilling stress redutionof ear numbers per square meter at tillering stage. Booting stage is themost crucial time for rice panicle development, will give a serious effect on rice panicle traitsdevelopment such as the ear length, primary branch number, secondary branch number and spikelets perpanicle was declined seriously, and significant reduction of the seed rate and output. Filling stagedecline of grain plumpness, ear weight and thousand seed weight.Booting stage chilling stress was significant duclined the yelid, followed by tillering stage andfilling stage. Dongnong423is the most sensitive varities under chilling stress at tillering stage, andDongnong425is most insensitive. Dongnong423and Wuyoudao No.1performance is not sensitiveunder chilling stress at booting stage, the yelid CRI were respectively76.39%and79.87%,Dongnong425and Dongnong427performance was stable, the yeild CRI were respectively89.62%and89.02%. The yeild of Wuyoudao No.1and Dongnong425under chilling stress at filling stage wasappreciable impact with the CK, and Tengxi138and Dongnong425is most stable under chilling stressat filling stage.