Genetic characteristics of (1) varieties
According to the research, chalkiness is controlled by a single gene, amylose content is controlled by a pair of major genes, high amylose is controlled by multiple genes, low amylose is controlled by a single dominant gene or a pair of major genes and several micro-genes, gelatinization temperature is controlled by 1 ~ 2 major genes or multiple genes, and so on.
(2) Environmental conditions
Especially, the temperature and light at the filling stage after heading have great influence on rice quality. For example, high temperature can reduce brown rice rate and milled rice rate by 1 ~ 3 percentage points, head rice rate by 3 ~ 10 percentage points or more, and increase chalky grain rate and chalkiness, thus increasing protein content. It also has great influence on amylose content and cooking quality.
(3) Cultivation measures
Such as sowing date, planting density, fertilization, irrigation, pesticide application, harvest time and processing conditions have certain effects on rice quality.