Assessment of Seed Yield and Quality of Winter Oilseed Rape Using Chlorophyll Fluorescence Parameters of Pods

Abstract

Abstract. Oilseed rape is one of the leading sources of vegetable oil in the world. Maximizing the seed yield and quality is crucial to improve the profit for farmers and meet the increasing consumer demand for healthy vegetable oil. However, the current evaluation process of seed yield and quality is tedious and inefficient due to its dependence on wet chemistry methods and/or manual measurements of small sample sizes. Because the photosynthesis of pods plays an important role in the accumulation of grain filling, this research aimed to evaluate the seed yield and quality of oilseed rape by using chlorophyll fluorescence (ChlF) parameters. The OJIP kinetics of rape pods were acquired in two independent experiments with different levels of nitrogen (N) application and different crop varieties, respectively. The JIP-test showed that the level of N fertilizer can influence the plant photosynthetic capacity and crop productivity, and the photosynthetic response also varied in the different varieties. The maximum quantum yield for primary photochemistry (Fv/Fm) was a sensitive indicator for evaluating the performance of photosystem II (PSII) activity with the different N applications and varieties. Increased quantum yield and efficiency with more active reaction centers (RCs) were observed under increased N application as well as with variety GY605, leading to higher energy utilization efficiencies. However, superior photosynthetic apparatus in pods is not recommended in high-quality seed breeding because it would increase the contents of glucosinolates and erucic acid. In addition, the random forest (RF) algorithm was proven to be effective in feature selection, and the selected fluorescence parameters mostly showed high correlations with seed yield and quality. These results demonstrate the potential of the ChlF method for assessing the seed yield and quality of oilseed rape at the early podding stage, which could also be useful for advancing crop breeding and improving agronomic management. Keywords: Agronomic management, Chlorophyll fluorescence, Crop varieties, JIP-test, Oilseed rape, Seed quality, Seed yield.