大穗型水稻品种7-37的光合特性及子粒灌浆特性研究

为了揭示高光效水稻品种大穗7-37的光合特性及子粒灌浆特性,以穗大生育期短的7-37、穗小生育期短的R122和穗大生育期长的R1126水稻品种为试验材料进行田间试验,结果表明大穗7-37在光合特性方面优势明显,尤其是胞间二氧化碳浓度C_i,花后25d前在3个品种中一直处于较低水平,剑叶一生中同化的CO₂ LSC是小穗R122的1.96倍,甚至比大穗R1126还多20%。在灌浆特性方面,大穗7-37在起始长势GR₀上就见有明显优势,虽然平均灌浆速率V_a略低于小穗R122,但明显高于大穗R1126,有效灌浆时间也比大穗R1126短。同时大穗7-37的穗长、每穗总粒数和着粒密度跟大穗R1126无显著差异,但都显著高于小穗R122。将一次枝梗和二次枝梗分开来看,大穗7-37在二次枝梗穗粒数的数量上有明显的优势,但千粒重与小穗R122、大穗R1126无显著差异,说明二次枝梗对叶源物质存在比较激烈的竞争,但仍可正常充实。由本试验可知较高的叶源量、较短的有效灌浆时间和丰富的二次枝梗穗粒数是大穗7-37具有高光效特性的主要原因。

Study on Photosynthetic Characteristics and Grain Filling Characteristics of Large Panicle Type Rice Variety 7-37

In order to reveal the photosynthetic and grain filling characteristics of high efficiency variety 7-37, large panicle 7-37 with short growth period, small panicle R122 with short growth period and large panicle R1126 with long growth period were used as the tested materials in the field experiment. The results showed that large panicle 7-37 had obvious advantages in photosynthetic characteristics, especially the intercellular carbon dioxide concentration C_i, always with lowest position in the three varieties before the 25d after flowering. Leaf source capacity ( LSC) of flag was 1.96 times higher than R122 and 20% higher than R1126. In grain filling characteristics, the 7-37 had obvious advantages in GR₀, although the V_a was a little lower than R122, significantly higher than R1126, and the effective filling time was also shorter than R1126. At the same time, the spike length, total number of kernels and grain density of 7-37 were no obvious difference with R1126, but significantly higher than R122. The primary branch and secondary branch were analyzed separately, which the secondary branch of 7-37 had obvious advantages on the total number of spike grain number, but there was no significant difference to R122 and R1126, which secondary branch to cytopathology substances existed more fierce competition, but still could be normal full. The tests indicated that the main reasons for large spike 7-37 with high photosynthetic efficiency were the higher leaf source capacity, the shorter effective filling time and the total number of secondary branch grains.