Utilizing the Genetic Potentials of Traditional Rice Varieties and Conserving Rice Biodiversity with System of Rice Intensification Management

Abstract

The genetic potentials of rice cultivars will need to be expressed to their fullest if global rice production is to be expanded enough by 2050 to meet the increased demand of the expanding population while the availability of land and water per capita dwindles. New and ‘improved’ rice varieties have contributed greatly to increased production over the past 50 years, but the rate of rice yield increase based on genetic changes has declined in recent decades compared with the early years of the Green Revolution. In fact, many rice consumers continue to prefer to consume ‘traditional’ rice varieties (referred to also as local, native, unimproved, or indigenous varieties) because of their taste, aroma, texture, and other qualities. Furthermore, many farmers prefer to cultivate these varieties because of their better adaptation to local climatic and soil conditions and their evolved resistance to endemic stresses. The practices that comprise the System of Rice Intensification (SRI), including transplanting rice seedlings at a young age, wide spacing between plants, keeping the soil well aerated rather than inundated, and enhancing soil organic matter, provide traditional rice varieties with micro-environments that are more favorable for the expression of their genetic and agronomic potentials. Interactions among rice plants, soil characteristics, water, energy, and other inputs improve the phenotypic and physiological performance of rice plants. This paper considers how the cultivation of traditional rice varieties with SRI methods can raise yields, reduce farmers’ costs of production, and generate higher incomes while contributing to the conservation of rice biodiversity.

The Spatiotemporal Variation in Biodiversity and Its Response to Different Future Development Scenarios: A Case Study of Guilin as an Internationally Renowned Tourist Destination in China

“…The InVEST model assumes that biodiversity is proportional to HQ and evaluates the capacity and potential of ecosystems to support species survival, reproduction, and activity by calculating HQ [31,32]. HQ is directly related to habitat suitability provided by LUC types [33], evaluating both the intensity of external threats and ecosystem sensitivity. The calculation formula is as follows:…”

Introduction to Special Issue on “The System of Rice Intensification (SRI)—Contributions to Agricultural Sustainability”

“…• Rice biodiversity: SRI management can make traditional rice varieties (also referred to as local, unimproved, native, indigenous, or heirloom varieties) that are being displaced by newer varieties considerably more successful agronomically and more competitive economically with modern, improved, or hybrid varieties. SRI's enhancement of the yield from 'unimproved' cultivars can make endangered varieties better able to persist and preserve the rice species' gene pool with market forces sustaining them [28].…”