The nutritional status and fluorescence characteristics of maize cultivars with different chlorophyll content and yields

Chlorophyll (Chl) is generally positively related to corn grain yields; however, light-leaf-colored maize may also achieve high yields. Thus, Chl is seemingly not a key parameter for maize producers. Modern maize cultivars (55) were divided into four types, based on grain yields and ear leaf SPAD readings. The results revealed that there was no correlation between the SPAD readings and corn grain yields across different maize cultivars. High-yield maize possessed higher nitrogen, phosphorus, and potassium accumulation and utilization compared to that of low-yield maize; the N-transport efficiency of low yield and high SPAD was the lowest among various types of maize. Under normal conditions, parameters determining the high yield of maize in a sequence was leaf dry mass, Chl fluorescence indices, and light absorption flux per leaf cross section. A higher absorption flux, accompanied by high energy dissipation ratios, reduced the difference of trapped transport flux between high-SPAD and low-SPAD maize at high yield levels. At the low yield level, a higher absorption flux per reaction center compensated for the loss of PSII reaction center numbers in low-SPAD maize.