Studies On The Characteristics Of Photosynthesis, Growth, And Development Of Chaling Wild Rice(Oryza Rufipogon Griff.)

The characteristics of photosynthesis, growth, anddevelopment of Chaling wild rice were studied with thesuper-high yield and high-yield cultivated rice(Liangyoupeijiu, Shanyou63, V46, 93-11, Nipponbare) ascontrols. The main results were as follows:(1)In the tillering stage, the net photosynthetic rate (P_n)of Chaling wild rice is lower than that of Shanyou63, but itis higher than that of V46 and is close to those of the restof the cultivars. The diurnal changes of P_n of Chaling wild ricehas a good performance, its Pn is higher than those of cultivarsin every measuring time on daytime. The P_nmax of Chaling wild riceis 29.5μmolCO₂·m^-2·s^-1 from the curve of PAR-P_n, and it hashigher AQY and LSP. The CE of Chaling wild rice is 0.1466 mol·m^-2·s^-1from the curve of CO₂-P_n, which is higher than those ofthe cultivars. Chaling wild rice has higher content ofchlorophyll. (2) In the flowering stage, the P_n of Chaling wildrice is higher than those of cultivars in the afternoon and athigh temperature (40℃and 45℃),indicating that Chaling wildrice has a stronger tolerance to high light intensity and hightemperature. The light saturation point (LSP) of Chaling wildrice is 1810μmol sphotons·m^-2·s^-1, which is higher than those of cultivars except 93-11, indicating that Chaling wild riceis a high LSP plant, and the light compensation point (LCP) ofChaling wild rice is 22.3μmol photons·^-2·s^-1,which has nosignificant difference to those of cultivars (20.1-23.7μmolphotons·m^-2·s^-1). The AQY of Chaling wild rice has nosignificant difference to those of cultivars neither. The CEand CO₂ saturation point of Chaling wild rice are 0.1511mol·m^-2·s^-1 and 644.5μmol·mol^-1 respectively, which arehigher than those of cultivars, implying that Chaling wild ricehas stronger ability of assimilating CO₂, and its CO₂compensation point(52.7μmol·mol^-1) is a little higher thanthose of cultivars, The chlorophyll content of Chaling wildrice is higher than those of cultivars. (3)In the filling stage,the P_n of Chaling wild rice is not very high, Although it is alittle higher than those of Nipponbare, V46 and Shanyou63, andis close to those of 9311 and Liangyoupeijiu. The diurnalchanges of Chaling wild rice have a better performance than thecultivars except Liangyoupeijiu. The LCP of Chaling wild riceis 24.3μmol photons·m^-2·s^-1, which is lower than those ofthe cultivars. The chlorophyll content of Chaling wild rice ismuch higher than those of the cultivars. (4)The nutrient growthrate of chaling wild rice is 0.88g/d, which is higher than those of the cultivars (0.23-0.37g/d).The number of tillers per plantrises up to 80 finally, the tillering ablity of Chaling wildrice is stronger than those of the cultivars. The promotingratio of high temperature to the heading of Chaling wild riceis 32%, and the promoting ratio of short sunshine to the headingof Chaling wild rice is 31.6%, both promoting ratios of Chalingwild rice are higher than those of the cultivars respectively,and both ratios reach to the grade of strong sensitivity. Basedon above results we conclude that Chaling wild rice has thestronger photosynthetic capacity, especially at hightemperature, which is a kind of wild rice resource that has thehigh efficiency photosynthesis, and has obvious vegetativeadvantages such as quick growth, strong tillering, and so on.