[Multivariate analysis of relationship between soil nutrient factors and fruit quality characte-ristic of 'Fuji' apple in two dominant production regions of China].

The objective of this experiment is to probe into the influence of soil nutrient contents on fruit quality features of 'Fuji' apple, screen major soil nutrient factors affecting fruit quality features, clarify the suitable soil nutrient content for good fruit quality indicators, and to provide theoretical basis in reasonable orchard soil fertilizer application for improving fruit qua-lity in the Circum-Bohai and Loess Plateau apple production regions in China. The soil nutrient contents and 'Fuji' fruit qualities were respectively analyzed at 66 commercial 'Fuji' apple orchards standard rootstock in the Circum-Bohai and Loess Plateau apple production regions of 22 counties in China from 2010 to 2011. The partial least squares regression (PLS) was used to screen major soil nutrient elements affecting fruit quality, and to establish regression equation of relationship between fruit quality and major soil nutrition factors. Linear programming was used to obtain optimum proposals of soil nutrient elements for good apple quality. The results showed that alkaline hydrolytic N, available P, Ca, Fe, and Zn of soil were significantly higher while pH and available K were significantly lower in Circum-Bohai region than in Loess Plateau apple production region. Soluble solid content in Loess Plateau was higher than in Circum-Bohai; moreover, ratio of soluble solids content and titratable acidity was lower. The soil available B in the Circum-Bohai and Loess Plateau apple production regions had positive effect on fruit mass, and total N had negative effect on fruit firmness. The soluble solid contents in the Circum-Bohai were mainly negatively affected by total N and positively by available B, while positively affected by available Ca and negatively by alkaline hydrolytic N in the Loess Plateau region. The desired soil nutrients for good fruit qualities were high avai-lable B, pH and suitable available K in the Circum-Bohai, and low total N, high alkaline hydrolytic N, available K, Fe and suitable available Zn and B in the Loess Plateau region. It was the key technical measures in soil nutrient management for good fruit quality to increase available B and pH, adjust available K in the Circum-Bohai, and to enhance alkaline hydrolytic N, available K, Fe, and to decrease pH, and adjust available Zn and B in the Loess Plateau region.