Effects Of Saline-Alkaline Stress On The Grain Filling Characteristics And Panicle Traits Of Northern Japonica

Saline-alkaline injury is one of the main natural disasters, which decreased thegrain yield badly. Northern japonicas were used to study the grain fillingcharacteristics and the panicle traits under different gradients of saline-alkaline stress.By cutting different leaves of both the saline-alkaline sensitive and tolerant ricevarieties, the grain filling characteristics of both superior and inferior grains and theprimary branch traits and secondary branch traits were studied to find out how the riceleaves playing as the source of the carbohydrates affect the panicle traits deemed asthe sink of the carbohydrates, so make the relationship between the source and sinkcleared. The results showed as follows:The grain filling characteristics of superior grains were affected milder comparedwith the inferior grains under mild, moderate and sever saline-alkaline stress for thesaline-alkaline sensitive and tolerant northern japonica rice varieties. What’s more,primary branch traits were more stable compared with secondary branch traits. Therank of the effects of leaves cutting on the grain filling characteristics and panicletraits was flag leave, second leave, and third leave in general.The superior grains were not affected by the leaves cutting significantlycompared with CK. The effects of leaves cutting on grain filling of inferior grainswere weaker for saline-alkaline tolerant rice variety compared with saline-alkalinesensitive rice variety, and in the anaphase of plant grow and development thesaline-alkaline tolerant rice variety had a potential grain filling ability.To study the japonica grain filling characteristics, the curve fitting technologyof Richards Equation was used. It turned out one of the parameters abbreviated as N,which was between0and1, showed out that the grain filling characteristics ofinferior grains was similar to the superior grains. They were almost at the same timeto fill the grains, and it could be synchronous.For the saline-alkaline tolerant variety, the primary branch traits were morestable than the secondary branch, and they didn’t show significant changes underdifferent gradients of saline-alkaline stress. The decrease of primary branch grainweight was mostly caused by the decrease of the1000-grain weight of primary branch, but the decrease of the secondary branch grain weight was owing to the reduce ofboth the secondary branch number and the1000-grain weight.For the saline-alkaline sensitive variety, both the primary and secondary branchtraits were restrained under different gradients of saline-alkaline stress. The decreaseof primary branch weight and secondary branch weight were owing to the degradationof both the branch number and the1000-grain weight.