Effect Of Tiller-Ihibitors On Yield And Quality Of Double-season Super Rice And Its Mechanism

With2widely used double-season super indica rice Jinyou458(early rice) and GanXin688(late rice) as test materials, the effects of tiller-inhibitor (with water as the CK)on the tiller occurrence and ear bearing,rice growth,grain filling,changes of endogenous phytohormones, yield and its formation, rice quality and nutrient absorption and so on were studied during the year2010-2011,at Test base of JiangXi Province Institute of Agricultural Sciences at TuJia Village,LiantTang Town, Nan Chang county, JiangXi province. The main results were as follows:1st, Tiller-Inhibitor can improve the yield, grain quality and the nutrient absorption of the double-season early and late rice.The yield constitution factor raised coordinately, the early rice increases yield9.93%while the late rice increases12.75%; Tiller-Inhibitor enhanced the grain's milling quality, the appearance quality, increased the amylose content, enhanced the gel consistency, reduced early rice's protein content and increase late rice's protein content. Tiller-Inhibitor can improved0.5(early rice)and1.5(early rice)grade points.Tiller-Inhibitor can escalate the entire starch RVA spectrum curve of the early and late rice. Tiller-Inhibitor can improve the RVA spectrum characteristic value peak value viscosity, the trough viscosity, breakdown, the final viscosity,setback as well as the pasting temperature, but the peak time to be invariable. Tiller-Inhibitor can enhance the N, P, K content, increased N, P, the K absorption of rice of the whole growing period.2nd, Tiller-Inhibitor can suppress obviously the occurrence of the tiller7/0and8/0of the early rice and the tiller8/0and9/0of the late rice, as well as the secondary tillers group, but actually increased the ear-bearing rate of these tillers. Tiller-Inhibitor increases the tiller yield proportion but decreases the stem yield proportion. It increases the primary tiller group yield proportion but decreases the secondary tiller group yield proportion.3rd, in a week time after the tiller-inhibitor sprayed, Tiller-Inhibitor can slow down the drop of the N content of leaf and the stem sheath.the iPA and Z+ZR content of the double-season rice straightly rise, the IAA content of the double-season rice straightly drops, tiller-inhibitor enhanced the extent of rising the iPA and the Z+ZR content and reduced the extent of droping the IAA content. After spraying the tiller-inhibitor,the GAs content of the leaf first arise then drop, the GAs content of leaf achieve the peak value1day after spraying the tiller-inhibitor. while the GAs content of the treatment of spraying the water drops straightly. After spraying the tiller-inhibitor, the ABA content of the leaf first drop then ascend, the ABA content of leaf achieve the bottom value1day after spraying the tiller-inhibitor.while the ABA content of the treatment of spraying the water ascend straightly.tiller-inhibitor enhance iPA, Z+ZR, ABA, IAA and the GAs content of the leaf in a week time after spraying the tiller-inhibitor.4th,the tiller-inhibitor can reduce the occurrence of the invalid and the low efficiency tillers obviously, the proportion of the middle and high effective tillers (single stem have4and above leaves) was much higher than that no tiller-inhibitor sprayed at the maxium tillers stage.At the maturity,the length of the ear, the grains per ear, the grain density of an ear, second branches and the glume flowers on the branches and the grain filling-rate on the branches that the tiller-inhibitor is sprayed obviously higher than has not sprayed.After sprayed the tiller-inhibitor, the plant height, the population biomass and the leaf area index of the middle and late growing stages,the3above leave temperature at the baby-earing stage were increased, enhance the percentage of light-penetrate, the leaf SPAD value, strengthened the photosynthesis ability, Increased the earing period effective LAI and the effective leaf area rate, the highly effective LAI and the highly effective leaf area rate, increased the proption of grain of leaves, increased the biomass weight and LAI of the booting stage and later growing stages, increase CGR of the mid and later growing stage and so on, but also increase the length of the rice base stem,reduces the thickness of the stem and reduced the anti-lodging ability.5th, Tiller-Inhibitor improved the grain filling accumulation,sped up the grain filling rate, increased the grain filling Richard equation parameter value A, R0, tmax. G, Wmax.G, Gmax, Gmean as well as T99, meanwhile increased in the grain endogenous hormone iPA, Z+ZR, IAA and the GAs content, reduced the ABA content. of the strong and weak grain of early and late rice.The above findings indicated Tiller-Inhibitor has a effect on the yield, the grain quality and so on to the double season super rice.Its main function mechanism was the tiller-inhibitor suppress effectively the occurrence of the invalid and the low efficiency tiller, promoted the growth of the effective tiller, established the highly effective photosynthesis rice population, absorbed more nutrients, promote the grain filling,thus improve the gain yield and the grain quality.