A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total le...A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total leaf area, and plant dry weight, but greatly increased density of root hairs and root top ratio. In addition, P-deficiency induced the significant enhancement of phosphorus utilization efficiency and the amount of proline, malondialdehye （MDA）, acid phosphatase （APase）, peroxidase （POD） and superoxide dismutase （SOD）, but the significant reduction of P uptake and soluable protein content. Since P-deficiency had smaller effects on the P-tolerant maize landraces DP-44, DP-32 and DP-33 as compared with P-sensitive landraces DP-29 and DP-24, it was demonstrated that differences of tolerance to P-deficiency existed among different maize landraces. The results based on the correlation analysis showed that the economic yield of maize landraces had relationships with their morphological and physiological characteristics under P-deficiency.展开更多
Phosphorus nutrient characteristics of different maize inbred lines to low-P stress were studied at stages of seedling, steming, earing, silking under pot culture. In the periods of seedling and steming, P uptake effi...Phosphorus nutrient characteristics of different maize inbred lines to low-P stress were studied at stages of seedling, steming, earing, silking under pot culture. In the periods of seedling and steming, P uptake efficiency was the main contributor to P tolerance, and the relative P content in P-tolerant genotypes, 99180 and 99239 were higher than that in sensitive genotype, 99152. At earing stage, P-tolerant genotypes, compared to P-sensitive ones, had higher accumulation of P in upper leaves. When came to the silking stage, P uptake and redistribution efficiency of P-tolerant genotypes were higher than those in 99152. The results also suggested that there are different mechanisms of P nutrient uptake and distribution in different P-tolerant genotypes. Inbred line 99239, according to the investigation, was considered as an efficient stock in the P-uptake while 99180 fallen to the efficient stock of P redistribution.展开更多
A system to control the release of phosphate in water was successfully established, based on solubility product of [Ca^2＋] and [PO4^3-] using tricalcium phosphate as P source in the hydroponic solution, and adding Ca...A system to control the release of phosphate in water was successfully established, based on solubility product of [Ca^2＋] and [PO4^3-] using tricalcium phosphate as P source in the hydroponic solution, and adding CaCl2 for supplementing extra Ca^2＋. The system, similar to soil solutions, was a P nutrient buffer solution with very low bioavailable P. The buffer solution induced the roots of both monocotyledon and dicotyledon species to grow abundant root hairs, 3 mm in maximum length. The monocotyledons were corn （Zea mays L.） （var. Yellow Rose）, wheat （Triticum aestivum L.） （var. Yanzhong 144）, Triticale secale L. （vat. Jingsong 5）, and ryegrass （Lolium rigidum L.） （var. Ruanni）, and the dicotyledons were Arabidopsis thaliana L. （var. Columbia）, white clover （Trifolium repens） （var. Kopu）, Lotus （Lotus peduncucatus Cav. Luliginosus Schkuhr） （var. Grasslands Maku）. For these species we proved that the root environment controls the induction of root hair formation. However, the hydroponic buffer solution failed to induce root hairs on the roots of onion （Allium cepa L.）. Other investigators have concluded that corn does not form root hairs in hydroponics, but abundant long root hairs on corn were induced by this buffer system. The roots with abundant long root hairs are called ＂hedgehog roots＂ because they have hairs everywhere just like a hedgehog.展开更多
文摘A field trial was conducted to investigate main morphological and physiological changes of different maize landraces to low-P stress at the stage of seedling. P-deficiency significantly decreased root volume, total leaf area, and plant dry weight, but greatly increased density of root hairs and root top ratio. In addition, P-deficiency induced the significant enhancement of phosphorus utilization efficiency and the amount of proline, malondialdehye （MDA）, acid phosphatase （APase）, peroxidase （POD） and superoxide dismutase （SOD）, but the significant reduction of P uptake and soluable protein content. Since P-deficiency had smaller effects on the P-tolerant maize landraces DP-44, DP-32 and DP-33 as compared with P-sensitive landraces DP-29 and DP-24, it was demonstrated that differences of tolerance to P-deficiency existed among different maize landraces. The results based on the correlation analysis showed that the economic yield of maize landraces had relationships with their morphological and physiological characteristics under P-deficiency.
基金This work was supported by the National 863 Program of China(2001AA241051).
文摘Phosphorus nutrient characteristics of different maize inbred lines to low-P stress were studied at stages of seedling, steming, earing, silking under pot culture. In the periods of seedling and steming, P uptake efficiency was the main contributor to P tolerance, and the relative P content in P-tolerant genotypes, 99180 and 99239 were higher than that in sensitive genotype, 99152. At earing stage, P-tolerant genotypes, compared to P-sensitive ones, had higher accumulation of P in upper leaves. When came to the silking stage, P uptake and redistribution efficiency of P-tolerant genotypes were higher than those in 99152. The results also suggested that there are different mechanisms of P nutrient uptake and distribution in different P-tolerant genotypes. Inbred line 99239, according to the investigation, was considered as an efficient stock in the P-uptake while 99180 fallen to the efficient stock of P redistribution.
基金the National Natural Science Foundation of China through grant numbers 30270785 948 Project 0ffice, Ministry of Agriculture, China, through grant numbers 201068.
文摘A system to control the release of phosphate in water was successfully established, based on solubility product of [Ca^2＋] and [PO4^3-] using tricalcium phosphate as P source in the hydroponic solution, and adding CaCl2 for supplementing extra Ca^2＋. The system, similar to soil solutions, was a P nutrient buffer solution with very low bioavailable P. The buffer solution induced the roots of both monocotyledon and dicotyledon species to grow abundant root hairs, 3 mm in maximum length. The monocotyledons were corn （Zea mays L.） （var. Yellow Rose）, wheat （Triticum aestivum L.） （var. Yanzhong 144）, Triticale secale L. （vat. Jingsong 5）, and ryegrass （Lolium rigidum L.） （var. Ruanni）, and the dicotyledons were Arabidopsis thaliana L. （var. Columbia）, white clover （Trifolium repens） （var. Kopu）, Lotus （Lotus peduncucatus Cav. Luliginosus Schkuhr） （var. Grasslands Maku）. For these species we proved that the root environment controls the induction of root hair formation. However, the hydroponic buffer solution failed to induce root hairs on the roots of onion （Allium cepa L.）. Other investigators have concluded that corn does not form root hairs in hydroponics, but abundant long root hairs on corn were induced by this buffer system. The roots with abundant long root hairs are called ＂hedgehog roots＂ because they have hairs everywhere just like a hedgehog.
