Liang Chao, Li Yimeng, Zhang Kunhao, Wu Zhouzhou, Liu Jiaxin, Liu Junfeng, Zhou Chanchan, Wang Shu, Li Fenghai, Sui Guomin
College of Agronomy, Shenyang Agricultural University, Shenyang 110866, China.
Liaoning Academy of Agricultural Sciences, Shenyang 110161, China.
Plants (Basel). 2023 Oct 7;12(19):3496. doi: 10.3390/plants12193496.
Dry direct seeding rice (DSR) is an emerging production system because of increasing labor and water scarcity in rice cultivation. The limited availability of rice cultivars suitable for dry direct seeding hampers the widespread adoption of this cultivation method in Northeast China. This study aimed to investigate grain production and plant characteristics associated with dry direct seeding rice. We conducted a field experiment on 79 rice cultivars in Shenyang City, Liaoning Province, Northeast China, in 2020 and 2021. This study found that the grain yield of the tested rice cultivars ranged from 5.75-11.00 t ha, with a growth duration lasting between 144-161 days across the cultivars. These cultivars were then categorized into high yielding (HY), medium yielding (MY), and low yielding (LY) based on daily yield by using Ward's hierarchical clustering method. The higher grain yield for HY compared to MY and LY was attributed to more spikelets per unit area. The HY alleviated the conflict between higher panicle density and larger panicle size by improving the seedling emergence rate and productive stem rate. It also significantly increased shoot biomass at maturity. The HY reduced the period between seeding and beginning of heading (BBCH 51) and the proportion of dry matter partitioned to the leaf at the heading stage. However, it also increased the accumulation of dry matter in the grain and the proportion of dry matter partitioned to the grain at maturity. Furthermore, the HY markedly increased the harvest index and grain-leaf ratio, which are beneficial to coordinate the source-sink relationship. A quadratic function predicted that 98 days is the optimum growth duration before heading (BBCH 51) for achieving maximum yield. In conclusion, for dry direct seeding rice, it is appropriate to select high-yielding inbred rice cultivars with shorter growth duration before heading (about 93-102 day), higher panicle number (about 450-500 × 10 ha), more spikelet number per panicle (about 110-130), higher seedling emergence rate (about 70-75%), higher productive stem rate (about 60-70%), and greater harvest index (about 50-55%).
由于水稻种植中劳动力和水资源日益短缺，旱直播水稻（DSR）成为一种新兴的生产系统。适合旱直播的水稻品种有限，这阻碍了这种种植方法在中国东北地区的广泛采用。本研究旨在调查与旱直播水稻相关的谷物产量和植株特性。2020年和2021年，我们在中国东北辽宁省沈阳市对79个水稻品种进行了田间试验。本研究发现，受试水稻品种的谷物产量在5.75 - 11.00吨/公顷之间，各品种的生长周期持续144 - 161天。然后，通过使用沃德层次聚类方法，根据日产量将这些品种分为高产（HY）、中产（MY）和低产（LY）三类。与中产和低产相比，高产的谷物产量更高归因于单位面积更多的小穗数。高产通过提高出苗率和有效茎率缓解了较高穗密度和较大穗型之间的矛盾。它还显著增加了成熟期的地上部生物量。高产缩短了播种至抽穗开始（BBCH 51）的时间以及抽穗期分配到叶片的干物质比例。然而，它也增加了谷物中干物质的积累以及成熟期分配到谷物的干物质比例。此外，高产显著提高了收获指数和粒叶比，这有利于协调源库关系。一个二次函数预测，抽穗前（BBCH 51）98天是实现最高产量的最佳生长周期。总之，对于旱直播水稻，适宜选择抽穗前生长周期较短（约93 - 102天）、穗数较多（约450 - 500×10³/公顷）、每穗小穗数较多（约110 - 130个）、出苗率较高（约70 - 75%）、有效茎率较高（约60 - 70%）且收获指数较大（约50 - 55%）的高产粳稻品种。
