Phosphorus Efficiency in Pasture Species. VII* Relationships between Yield and P Uptake and Root Parameters in 'Itvo Accessions of White Clover
Phosphorus Efficiency in Pasture Species. VII* Relationships between Yield and P Uptake and Root Parameters in 'Itvo Accessions of White Clover
复制标题
牧草物种的磷效率。
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
D. Godwin
中科院分区：
文献类型：
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作者：
G. Blair;D. Godwin
缺乏根系生长数据和根系参数与磷吸收之间的关系是理解和模拟作物和饲料植物磷效率的主要限制。进行了一个实验，其中两个白色三叶草（白三叶草，奇斯威克和Ladino）品种在盆栽中生长在以低（P5 [kg ha-1]）或高（P40）P施用率施肥的缺P土壤中。在移植后10、16、22、28、34和40天收获植物，并从盆中收获顶部和根。根成员的详细措施，在10，16和22天，这些与磷的吸收。干重的加入是相同的两个速率之间的P，直到第28天。40 d时，Ladino的顶部产量高于P40时的奇斯威克。从第16天开始，根干重随着施磷量和施磷时间的增加而增加。仅在P5的第16天和第34天收获时，根生长出现显著差异。拉迪诺往往有一个更大的平均磷吸收随着时间的推移比奇斯威克在两个P水平。磷吸收量与地上部和根系干重、根长、根数、根体积和表面积呈显著正相关，与平均根径和平均单根长呈显著负相关。Ladino在低磷条件下的根伸长速率大于奇斯威克，这可能解释了Ladino在低磷条件下在本试验后期收获时对磷的吸收。在本研究中检查的两个加入根的长度，直径和数量的变化，随着时间的推移，在响应P，反映了某种形式的协调。奇斯威克倾向于产生许多短根，而拉蒂诺较少长根。只有小的差异，每单位根长的磷吸收量进行了测量，这表明，总根长或根延伸率是在这些加入的白色三叶草的总磷吸收量的主要决定因素。
Lack of data on root growth and relationships between root parameters and P uptake are major limitations to understanding and modelling P efficiency in crop and forage plants. An experiment was conducted whereby two accessions of white clover (Trifolium repens, Chiswick and Ladino) were grown in pots in a P deficient soil fertilized with a low (P5 [kg ha-']) or high (P40) P application rate. Plants were harvested at 10, 16, 22, 28, 34 and 40 days after transplanting and tops harvested and roots recovered from the pots. Detailed measures of root members were made at 10, 16 and 22 days and these correlated with P uptake. Dry weight of tops of accessions was the same between the two rates of P until day 28. At 40 days, the tops yield of Ladino was higher than Chiswick at P40. Root dry weight increased with increasing P application rate and time from day 16 onwards. Significant differences in root growth only occurred at the 16 and 34 day harvests at P5. Ladino tended to have a greater mean P uptake over time than did Chiswick at both P levels. P uptake was found to be positively correlated with shoot and root dry weight, root length, root number, root volume and surface area, and negatively correlated with mean root diameter and mean length per root. Root extension rate at low P in Ladino was greater than that in Chiswick, which may explain the greater P uptake by Ladino at low P at later harvests in this experiment. The changes in length, diameter and number of roots in the two accessions examined in this study, with time, in response to P, reflect some form of coordination. Chiswick tended to produce many short roots whilst Ladino fewer long roots. Only small differences in P uptake per unit root length were measured, which suggest that total root length or root extension rate is the primary determinant of total P uptake in these accessions of white clover.