Abstract
Increasing resistance to aging is conducive to seed storage and germination rate of crop. Meanwhile, the resistance to aging is one of the important adaptive mechanisms of weed to thrive in farmland. Weedy rice (Oryza sativa f. spontanea) and cultivated rice (Oryza sativa L.) provide a unique pair demonstrating a weed and conspecific model crop that can be used to study the aging resistance of plants across a diverse geographical range. Chinese weedy rice derived from de-domestication of cultivated rice has rapidly risen to malignant weeds, though the hazard has only been reported for about 20 years. Whether weedy rice rapidly evolves higher seed aging resistance than cultivated rice during the process of dedomestication, which is conducive to its persistence in rice fields, is still unclear. In this experiment, the seeds of weed rice populations and their co-existing rice varieties were collected from 61 regions of China and germinated under normal and high temperatures for consecutive four years (2013–2016). Our study found that the aging resistance of weedy rice was higher than that of the co-existing rice cultivars, and weedy rice may have evolved a different aging resistance mechanism than rice cultivars and could be used as a germplasm resource to cultivate aging-resistant rice. The indica-type has strong aging resistance and no dormancy, while the japonica type has weak aging resistance and a little weak dormancy. Thus, by introducing indica-type aging-resistant alleles into japonica rice, cultivation of aging-resistant japonica rice could be possible.
Density Dependent Competitive Interactions between Weedy Rice (Oryza Sativa F. Spontanea) and Cultivated Rice in Sri Lanka
