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Accueil du site → Doctorat → Chine → 2020 → Influence of Plant Growth Regulators and Nitrogen Application on the Hydrocyanic Acid and Morpho-physiological Parameters in Drought-stressed Sorghum Species

Southwest University (2020)

Influence of Plant Growth Regulators and Nitrogen Application on the Hydrocyanic Acid and Morpho-physiological Parameters in Drought-stressed Sorghum Species

ABDELSALAM ABDELWAHAB ABDELSALAM SHEHAB;

Titre : Influence of Plant Growth Regulators and Nitrogen Application on the Hydrocyanic Acid and Morpho-physiological Parameters in Drought-stressed Sorghum Species

Auteur : ABDELSALAM ABDELWAHAB ABDELSALAM SHEHAB;

Grade : Doctoral Dissertation 2020

Université : Southwest University

Résumé partiel
Sorghum(Sorghum bicolor Moench)is widely distributed in arid and semi-arid areas,mainly being used for food,forage,bioenergy,and baijiu production.However,water shortage associated with the climate changes severely influenced sorghum production all over the world.The increase of cyanogenic glycosides(CGs)in forages would increase the risk of hydrocyanic acid(HCN)to animals,which would prohibit the activity of metalloenzymes in animals,especially cytochrome oxidase and the definitive enzyme in the respiratory electron transport chain,and thus lead to poisoning,mild to severe illness,and even death.Droughts not only reduce the biomass of sorghum but also increase the risk of HCN toxicity to animals,mainly due to increased HCN content in drought-stressed plants.Therefore,it is important to control the contents of CGs in fodder plants and to balance between defensive responses and food safety.Therefore,three experiments were conducted in this study,including one field experiment and two pot experiments,aiming to elucidate the potential of plant growth regulators and nitrogen applications in balancing obtaining suitable plant biomass and harvesting forages with low HCN accumulation.In field experiment,the variations of HCN contents in 12 sorghum genotypes(10 sweet sorghum cultivars,one sudangrass and one forage sorghum)were investigated at jointing,filling and ripening stages under rain-fed conditions.In pot experiments,three sorghum genotypes,one sweet sorghum,one sudangrass and one forage sorghum,which differed greatly in their leaf HCN contents in fields,were further selected.In the first pot experiment,about 100μg/L abscisic(ABA)and 100μg/L methyl jasmonate(MeJA)were sprayed separately or together twice on drought-stressed(50%field capacity(FC)and well-watered conditions)plant leaf.The drought lasted for 15 days.In the second pot experiment,nitrogen was applied(0,60,90 and 120kg N ha-1)on plants under two water conditions(drought,55%FC ;well-watered conditions).The pot experiments replicated four times.The physiological responses of plant growth regulators and nitrogen applications were evaluated in mitigating the concentrations of HCN in drought-stressed plants.The main results were as follows:In field experiment,sorghum species differed greatly in their leaf HCN contents in fields,ranging from 31 mg kg-11 to 482 mg kg-1.The HCN accumulation showed a reducing trend from the jointing stage to filling stage and then showed an increasing trend in some sorghum genotypes,particularly in two sweet sorghums(America Giant and Sea lion).In first pot experiment,hydrocyanic acid and soluble protein accumulation in three genotypes increased significantly under water-stressed conditions.The application of exogenous hormones overall reduced the HCN contents from both plants of control and those subjected to drought in sweet sorghum and sudangrass.The HCN contents in ABA treated plants were significantly higher than those in MeJA treated plants.Plants sprayed with ABA and/or MeJA significantly reduced the soluble protein content in forage sorghum

Mots clés : Drought; Hydrogen cyanide(HCN); Nitrogen fertilization; Physiological responses; Sorghum bicolor; ABA; MeJA

Présentation (CNKI)

Page publiée le 15 juin 2021