Impact of Temperature Increase during Filling Period on Cadmium Transportation andAccumulation and Yield of Rice

Yin Xinfang; Zhang Yusheng; Yin Xinjun; Wang Xin'ao; Ao Hejun

doi:10.14083/j.issn.1001-4942.2025.05.017

Abstract：In order to explore the impact of temperature changes in later growth period of rice on yield and cadmium transportation and accumulation,three conventional late rice varieties(v1,v2,v3)with differ-ent cadmium absorption capacity were used as materials,and the pot experiment was conducted in the artificial climate room of the Rice Institute of Hunan Province in 2023 by setting two temperature treatments as control(CK,day 30℃/night 20℃)and temperature increase treatment(day 35℃/night 25℃).The impact of temperature increase from full heading period to mature period on yield traits and cadmium content,accumula-tion and transportation of rice were studied.The results showed that temperature increase significantly reduced the yield of v1,v2 and v3 by 35.3%,33.1%and 22.2%,respectively compared with their CK,and reduced the seed rate,1 000-grain weight and kernel number per ear.Temperature increase promoted the cadmium ab-sorption in roots,stems and leaves of the three varieties during mature period.The cadmium content in roots increased by 177.0%,119.5%and 142.3%compared with their CK,respectively,which were up to signifi-cant level.The cadmium content in stems and leaves of v1 and v3 increased by 131.7%and 75.5%compared with their CK,and reached significant level.Temperature increase inhibited the accumulation of cadmium into grains.The transfer coefficient of cadmium from stems and leaves to brown rice decreased by 78.4%and 57.1%in v1 and v3 compared with their CK.Cadmium accumulation in brown rice of the three varieties de-creased by 67.5%,21.7%and 32.4%,respectively.During temperature increase,the contents of malondial-dehyde(MDA),non-protein thiols(NPT),glutathione(GSH),and phytochelatins(Pcs)in rice flag leaves were significantly improved,and the synthesis and transportation of photosynthetic products were reduced.In summary,temperature increase promoted the cadmium absorption of roots and its transportation to stems and leaves,which inhibited the synthesis and transportation of photosynthates in rice,thereby reduced the yield and cadmium contentin brown rice.