英语语法分析

There is good correlation between chlorophyll content and SPAD values.

叶绿素含量与SPAD值有很好的相关关系。

The SPAD-502 chlorophyll meter appears promising for rapid, on-farm analysis of crop nitrogen status.

叶绿素仪（SPAD-502）的出现使通过无损伤的田间速测对作物进行氮营养诊断成为可能。

Chlorophyll content was 1.2 SPAD, and the chloroplast did not develop, with only small vesicle-like structures.

结果发现叶绿素平均含量仅为1.2（SPAD），而叶绿体也不能正常发育仅有囊泡状结构。