Effects of source-sink regulation and nodal position of the main crop on the sprouting of regenerated buds and grain yield of ratoon rice

Abstract

Ratoon rice (Oryza sativa L.) is the production of a second season rice that utilizes the dormant buds surviving on the stubble left behind after the harvest of the main crop. However, the sprouting mechanism of regenerated buds at separate nodes is rarely reported. Field experiments were conducted to examine the effects of leaf-cutting and spikelet thinning on the sprouting of regenerated buds at the separate node, the contributions of regenerated panicles at the separate node to the total grain yield in the ratoon crop, and the associated mechanism. The results showed that the contribution of separate node yields to the total grain yield in the ratoon crop was D2 (panicles regenerated from the 2nd node from the top) >D3 (panicles regenerated from the 3rd node from the top) >D4 (panicles regenerated from the lower nodes below the 3rd node), and the contribution of D2 and D3 made up approximately 80% of the total yield in the ratoon crop. In addition, the effect of leaf-cutting treatment and spikelet-thinning treatment on the grain yield of ratoon season was mainly realized by regulating the relative contribution rate of D2 and D4 grain yield to the total yield of ratoon season. Further analysis indicated that the sprouting of regenerated buds at the D2 node was mainly affected by the content of CTK, while D3 was mainly regulated by GAs and CTK, and D4 was mainly regulated by ABA and CTK. However, only the CTK content in stems and buds was positively correlated with single bud length and bud number at each nodes. These results indicated that CTK might be the main signal regulating the sprouting of regenerated buds and the grain yield at separate nodes, which might change the transport of assimilates to stems and buds.

Physiological Properties of Perennial Rice Regenerating Cultivation in Two Years with Four Harvests

“…In a related study, the ABA content in rice crops increased steadily, triggering a sharp increase in the crop panicle weight 20 days after heading [42]. Our investigation showed that ABA exhibited a linear increase in both PR25 and AR2640, exhibiting the highest peak 22 d after harvest, especially at low stubble heights, corroborating He et al's work [43], wherein they documented that ABA was responsible for ratoon rice panicle regeneration. This behavior confirms Fallah et al's recent findings, wherein they mentioned that ABA enrichment contributed to the promotion of sugarcane ratoon crop growth [41].…”

Interaction of Phytohormones and External Environmental Factors in the Regulation of the Bud Dormancy in Woody Plants

“…The buds remain incapable of initiating sprouting and generating fresh branches or foliage. However, if the adjacent tissue is removed, the dormant buds can resume growth quickly [16,17]. Significant progress has been made in studying the complexities of paradormancy, especially in understanding the mechanisms behind apical dominance [18][19][20].…”

Difference in Cd accumulation among varieties with different growth duration corresponding to typical agro-climate condition in rice ratooning system

“…Because ratoon rice has the advantages of saving costs, increasing income, increasing yield and reducing labor intensity, people have begun to focus on ratoon rice again. Owing to the selection of high-yield and high-quality varieties of ratoon rice, the optimization of nutrient and water management, research and development of comprehensive pest and disease prevention and control technology, and the matching of agricultural machinery and agronomy, the yield of ratoon rice has been greatly improved ( Huang et al., 2022 ; He et al., 2023 ). The long grain filling time during the ratoon crop of ratoon rice allows sufficient accumulation of photosynthetic products, which is conducive to the formation of good rice quality ( Li et al., 1990 ).…”