[Objective] The aim of this study is to reveal the salt resistance of castor. [Method] Under salt stress, the growth, osmotic potential, chlorophyll fluorescence parameters, Na^+ and K^+ uptakes and transports in the ...[Objective] The aim of this study is to reveal the salt resistance of castor. [Method] Under salt stress, the growth, osmotic potential, chlorophyll fluorescence parameters, Na^+ and K^+ uptakes and transports in the seedlings of two Ricinus communis varieties (cultivar castor ‘Zibi 6’ and wild castor which grew naturally in coastal saline-alkali land), were comparatively studied. [Result] Wild castor preformed better in halophilism than that of cultivar castor Zibi 6 under the NaCl treatment. One of the salt tolerant mechanisms of castor is to improve K^+ uptake and transport to overground portion, thus to maintain K^+/Na^+ homeostasis in leaves; on the other hand, the high stability of Photoreaction System Ⅱ (PS Ⅱ) plays a key role in maintaining the leaf photosynthetic rate under salt stress. [Conclusion] The results of this study provided theoretical basis for the extension and application of castor in saline beach.展开更多
The field experiments were carried out to investigate the dynamics and models of N, P and K absorption for the cotton plants with a lint of 3 000 kg ha-1 in Xinjiang. The main results were as follows: The contents of ...The field experiments were carried out to investigate the dynamics and models of N, P and K absorption for the cotton plants with a lint of 3 000 kg ha-1 in Xinjiang. The main results were as follows: The contents of N, P2O5, K2O in cotton leaves, stems, squares and bolls decreased obviously with the time over the whole growth duration and the falling extent was greater in high-yield cotton than in CK. Contents of N in leaves, squares and bolls, in particular in the leaves of fruit-bearing shoot was higher in high-yield cotton than in CK. Contents of P2O5 in squares and bolls and that of K2O in stems were higher in high-yield cotton than in CK during the whole growing period. The accumulations of N, P2O5 and K2O in the cotton plants could be described with a logistic curve equation. There was the fastest nutrient uptake at about 90 d for N, 92 d for P2O5 and 85 d for K2O after emergence, respectively. Total nutrient accumulation of N, P2O5 and K2O was 385.8, 244. 7 and 340.3 kg ha-1, respectively. Approximately 12. 5 kg N, 8. 0 kg P2O5 and 11.1 kg K2O were needed for producing 100 kg lint with the leaves and stems under the super high yield condition of 3 000 kg ha-1 in Xinjiang.展开更多
A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanc...A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanced rice vegetative growth and increased grain yield and IKUE under low potassium. Addition of higher rate of NaCl had a negative effect on the growth of the K-efficient rice genotype, but did not for the K-inefficient genotype. Under low-K stress, higher NaCl decreased IKUE of the K-efficient rice genotype but increased IKUE for the K-inefficient genotype. At tillering stage and under low-K stress, adding NaCl increased K and Na contents and decreased the ratio of K/Na for both genotypes. At harvesting stage under low-K stress, adding NaCl increased K and Na contents and K/Na ratio for the K-efficient genotype but decreased the K/Na ratio for the K-inefficient genotype. The accumulated Na was mostly deposited in the roots and sheaths. At tillering stage, the K and Na contents and the K/Na ratios in different parts for both genotypes decreased in the following sequence: K+ in sheaths > K+ in blades > K+ in roots; Na+ in roots > Na+ in sheaths > Na+ in blades; and K/Na in sheaths 》 K/Na in roots. The K-efficient genotype had a lower K/Na ratio in roots and sheaths than the K-inefficient genotype under low-K stress. At harvesting stage, K and Na contents in grains were not affected, whereas K/Na ratio in the rice straws was increased for the K-efficient genotype but decreased for the K-inefficient genotype by Na addition. However, this was not the case under K sufficient condition.展开更多
文摘[Objective] The aim of this study is to reveal the salt resistance of castor. [Method] Under salt stress, the growth, osmotic potential, chlorophyll fluorescence parameters, Na^+ and K^+ uptakes and transports in the seedlings of two Ricinus communis varieties (cultivar castor ‘Zibi 6’ and wild castor which grew naturally in coastal saline-alkali land), were comparatively studied. [Result] Wild castor preformed better in halophilism than that of cultivar castor Zibi 6 under the NaCl treatment. One of the salt tolerant mechanisms of castor is to improve K^+ uptake and transport to overground portion, thus to maintain K^+/Na^+ homeostasis in leaves; on the other hand, the high stability of Photoreaction System Ⅱ (PS Ⅱ) plays a key role in maintaining the leaf photosynthetic rate under salt stress. [Conclusion] The results of this study provided theoretical basis for the extension and application of castor in saline beach.
基金supported by the National Key Technologies R&D Program in 10th Five-year Plan of China(2001BA507A)the National Natural Sicence Foundation of China(39760040).
文摘The field experiments were carried out to investigate the dynamics and models of N, P and K absorption for the cotton plants with a lint of 3 000 kg ha-1 in Xinjiang. The main results were as follows: The contents of N, P2O5, K2O in cotton leaves, stems, squares and bolls decreased obviously with the time over the whole growth duration and the falling extent was greater in high-yield cotton than in CK. Contents of N in leaves, squares and bolls, in particular in the leaves of fruit-bearing shoot was higher in high-yield cotton than in CK. Contents of P2O5 in squares and bolls and that of K2O in stems were higher in high-yield cotton than in CK during the whole growing period. The accumulations of N, P2O5 and K2O in the cotton plants could be described with a logistic curve equation. There was the fastest nutrient uptake at about 90 d for N, 92 d for P2O5 and 85 d for K2O after emergence, respectively. Total nutrient accumulation of N, P2O5 and K2O was 385.8, 244. 7 and 340.3 kg ha-1, respectively. Approximately 12. 5 kg N, 8. 0 kg P2O5 and 11.1 kg K2O were needed for producing 100 kg lint with the leaves and stems under the super high yield condition of 3 000 kg ha-1 in Xinjiang.
基金Project (No. 315200) supported by the the Outstanding Young Scientist Grant of Natural Science Foundationof Zhejiang Pr
文摘A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanced rice vegetative growth and increased grain yield and IKUE under low potassium. Addition of higher rate of NaCl had a negative effect on the growth of the K-efficient rice genotype, but did not for the K-inefficient genotype. Under low-K stress, higher NaCl decreased IKUE of the K-efficient rice genotype but increased IKUE for the K-inefficient genotype. At tillering stage and under low-K stress, adding NaCl increased K and Na contents and decreased the ratio of K/Na for both genotypes. At harvesting stage under low-K stress, adding NaCl increased K and Na contents and K/Na ratio for the K-efficient genotype but decreased the K/Na ratio for the K-inefficient genotype. The accumulated Na was mostly deposited in the roots and sheaths. At tillering stage, the K and Na contents and the K/Na ratios in different parts for both genotypes decreased in the following sequence: K+ in sheaths > K+ in blades > K+ in roots; Na+ in roots > Na+ in sheaths > Na+ in blades; and K/Na in sheaths 》 K/Na in roots. The K-efficient genotype had a lower K/Na ratio in roots and sheaths than the K-inefficient genotype under low-K stress. At harvesting stage, K and Na contents in grains were not affected, whereas K/Na ratio in the rice straws was increased for the K-efficient genotype but decreased for the K-inefficient genotype by Na addition. However, this was not the case under K sufficient condition.
