Impacts of chilling at the tillering phases on rice growth and grain yield in Northeast China

Abstract

Chilling is a major constraint on rice production in mountainous regions of the tropics and in the temperate rice‐growing zones of the world. In this study, our goal is to quantify the impacts of chilling at the tillering phases on rice growth and grain yield. In 2017 and 2018, we conducted a factorial chilling treatment at four temperatures (T1, T2, T3 and T4) and four duration days (D2, D4, D6 and D8) on rice plants at the early, middle and late tillering phases. The results showed that chilling at the tillering phases delayed rice growth period. The rice grain yield slightly increased with decrease in chilling temperature but significantly decreased with increase in chilling duration at the tillering phases. For the chilling treatment at T1 (lowest temperature), the D2 (shortest duration) had positive effects on rice yield, while the D8 (longest duration) had adverse effects on rice yield. The middle and late tillering phases were the critical growth phases for rice spike numbers formation, with the increase in temperature and duration, the rice spike numbers per plant significantly decreased. The decrease in chilling temperature and increase in chilling duration both decreased rice thousand‐grain weight under chilling treatments at tillering phases. The prolongation of days from emergence to flowering led to increase in rice aboveground biomass per plant and allocation index of stem; however, the decrease in days from flowering to maturity led to reduction in allocation index of panicle and grain yield under chilling treatments at tillering phases. This study could help farmers to better understand the impacts of chilling on rice growth and yield, especially for rice that are prone to chilling.

Transcriptome and Metabolome Analyses Reveal Ascorbic Acid Ameliorates Cold Tolerance in Rice Seedling Plants

“…Exposure to cold stress during the seedling, flowering, and grain-filling stages in rice was found to weaken the efficiency of light utilization in the leaves at these stages, lower the photosynthetic rate in rice leaves, inhibit the synthesis and transport of assimilates, affect the growth rate of rice, and cause an increase in the source/sink growth ratio, leading to a reduction in rice production [4]. Similar results were also found in other studies of rice subjected to cold stress at different growth stages [5,6]. The occurrence of late spring coldness during the rice seedling stage severely affects the safe production of rice.…”

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

“…The shortened reproductive growth stage will affect the formation of spikelets. Coupled with the reduced accumulation of nutrients in the early stage, and the weak single stem at the heading stage, this will aggravate the degradation of spikelets, which is not conducive to the accumulation of substances in the panicle ( Guo et al., 2022 ).…”

An experimental study on the effects of intermittent chilling at different growth stages on rice yield in Northeast China

“…Once the rice plants in the pots reached the targeted tillering (25 days after transplanting), booting (the upmost pulvinus interval of main stems are −5~−7 cm) and flowering (the main stems bloom up to 10%) stages, they were transferred into naturally lit growth chambers (4 m long, 4 m wide and 3.5 m high) for artificial chilling treatment (Figure 1a). Based on previous research (Guo et al, 2022; Shi, Guo, Wang, et al, 2022) and historical meteorological data (Figure S1), we selected the average temperature of 12°C (extreme chilling temperature level) and 18°C (chilling temperature level that may be encountered in actual production) as the treatment temperature and the intermittent days were set to 2 days, the diurnal temperature was 10°C (Figure S2). There were four chilling durations of D2, D4, D6 and D8 for the continuous and intermittent chilling treatments.…”