Selection and Yield Formation Characteristics of Dry Direct Seeding Rice in Northeast China
Chao Liang1, Yimeng Li1, Kunhao Zhang1
1College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China.
Plants (Basel, Switzerland)
|October 14, 2023
Summary
Selecting high-yielding japonica rice cultivars is key for dry direct seeding (DSR) success. These cultivars offer better grain yield by optimizing plant traits like seedling emergence and harvest index.
Area of Science:
- Agronomy
- Plant Breeding
- Crop Physiology
Background:
- Dry direct seeding (DSR) rice cultivation is expanding due to labor and water scarcity.
- Limited availability of suitable japonica rice cultivars hinders DSR adoption in Northeast China.
Purpose of the Study:
- Investigate grain production and plant characteristics of japonica rice cultivars under dry direct seeding conditions.
- Identify optimal traits for high-yielding DSR cultivars in Northeast China.
Main Methods:
- Field experiment with 79 japonica rice cultivars in Shenyang, China (2020-2021).
- Cultivar categorization into high (HY), medium (MY), and low (LY) yielding groups using Ward's hierarchical clustering.
- Analysis of plant characteristics including yield, growth duration, biomass allocation, and harvest index.
Main Results:
- Grain yield varied from 5.75-11.00 t ha⁻¹ with growth durations of 144-161 days.
- High-yielding cultivars (HY) achieved greater yield through increased spikelets per area, improved seedling emergence, and higher productive stem rates.
- HY cultivars demonstrated enhanced shoot biomass, optimized dry matter partitioning to grain, and increased harvest index.
Conclusions:
- High-yielding japonica inbred rice cultivars with specific traits are suitable for DSR.
- Optimal traits include shorter pre-heading duration (93-102 days), higher panicle number (450-500 × 10⁴ ha⁻¹), more spikelets per panicle (110-130), higher emergence and productive stem rates (70-75% and 60-70%), and a greater harvest index (50-55%).
