Trends in leaf photosynthesis in historical rice varieties developed in the Philippines since 1966
Trends in leaf photosynthesis in historical rice varieties developed in the Philippines since 1966
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DOI：
10.1093/jxb/erm192
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发表时间：
2007-10-01
影响因子：
6.9
通讯作者：
Murchie, E. H.
中科院分区：
文献类型：
--
作者：
Hubbart, S.;Peng, S.;Murchie, E. H.
作物产量的提高很少与叶片光合作用联系在一起。然而，在某些作物中，如水稻，预计将需要增加光合作用速率来支持未来的粮食产量潜力。为了了解水稻产量提高与叶片光合作用的关系，利用控制环境条件，对1966~1995年从国际水稻研究所(IRRI)引进的10个品种和1个新育成的品系进行了栽培试验。采用两种生长光强：强光(1500mmolm(-2)S(-1))和弱光(300mmolm(-2)S(-1))。测定了主茎第9叶的气体交换、叶片蛋白质、叶绿素和叶片形态。单位叶面积的光饱和光合作用速率(P-max)、气孔导度(G)、核酮糖二磷酸羧基加氧酶(Rubisco)含量和叶片总蛋白含量在强光下植株间差异较大。值得注意的是，在1966-1980年间，P-max、g、叶蛋白、叶绿素和Rubisco含量下降。1980年后发布的这些品种的价值有所回升。这一显着的趋势与之前发表的一项观察结果相吻合，即1980年前发布的IRRI品种的产量与收获指数相关，而1980年后发布的品种的产量与生物量相关。P-max与g和Rubisco含量均呈显著正相关。在强光和弱光生长的植物(光驯化)之间观察到了很大的差异。高光植物对P-max的光驯化‘范围’与P-max呈正相关。结果表明：(1)叶片光合作用可能受到育种策略的系统性影响；(2)当产量受到生物量生产而不是分配的限制时，P-max是一个有用的增产目标；(3)光适应能力与较高的P-max值有关。
Crop improvement in terms of yield is rarely linked to leaf photosynthesis. However, in certain crop plants such as rice, it is predicted that an increase in photosynthetic rate will be required to support future grain yield potential. In order to understand the relationships between yield improvement and leaf photosynthesis, controlled environment conditions were used to grow 10 varieties which were released from the International Rice Research Institute (IRRI) between 1966 and 1995 and one newly developed line. Two growth light intensities were used: high light (1500 mu mol m(-2) s(-1)) and low light (300 mu mol m(-2) s(-1)). Gas exchange, leaf protein, chlorophyll, and leaf morphology were measured in the ninth leaf on the main stem. A high level of variation was observed among high light-grown plants for light-saturated photosynthetic rate per unit leaf area (P-max), stomatal conductance (g), content of ribulose bisphosphate carboxylase-oxygenase (Rubisco), and total leaf protein content. Notably, between 1966 and 1980 there was a decline in P-max, g, leaf protein, chlorophyll, and Rubisco content. Values recovered in those varieties released after 1980. This striking trend coincides with a previous published observation that grain yield in IRRI varieties released prior to 1980 correlated with harvest index whereas that for those released after 1980 correlated with biomass. P-max showed significant correlations with both g and Rubisco content. Large differences were observed between high light- and low light-grown plants (photoacclimation). The photoacclimation 'range' for P-max correlated with P-max in high light-grown plants. It is concluded that (i) leaf photosynthesis may be systematically affected by breeding strategy; (ii) P-max is a useful target for yield improvements where yield is limited by biomass production rather than partitioning; and (iii) the capacity for photoacclimation is related to high P-max values.