Thailand rosewood(Dalbergia cochinchinensis)is a vulnerable high value tree species in subtropical and tropical Southeast Asia.The demand for the rehabilitation of the natural habitat of the species requires high-qual...Thailand rosewood(Dalbergia cochinchinensis)is a vulnerable high value tree species in subtropical and tropical Southeast Asia.The demand for the rehabilitation of the natural habitat of the species requires high-quality seedlings.However,current fertilizer regimes tend to deliver a coarse rate of fertilizers that result in a low uptake efficiency and a high risk of nutrient excess.Exponential fertilization is an effective approach to promote seedling quality through identifying an optimum dose out of a range of applications.In this study,Thailand rosewood seedlings were cultured in a mixed substrate of perlite,vermiculite,and peat(2:2:3,v/v/v)and received exponential fertilization from 0(control),through 100,200,300,400,and 600 mg nitrogen(N)per plant over a four-month cultural rotation.Height,diameter,and shoot biomass increased with fertilizer rate and were maximized at 300 mg N per plant.This application also reduced nutrient deficiencies and avoided excess supply compared to higher rates.Polysaccharide,proline,and anti-oxidation enzyme activities tended to be greater in unfertilized controls or in over-fertilized high dosages,with lower activities around 100–300 mg N plant(-1).Application of 300 mg N per plant was identified as the optimum dosage as it maximized nutrient reserves,polysaccharide and proline contents,and anti-oxidants without causing any symptoms from excess fertilizer toxicity.Future work is required to identify the effects of N-fixation on the formation of nutritional reserves in Thailand rosewood seedlings subjected to exponential fertilization.展开更多
Objective To study the flavonoids from the heartwood of Dalbergia cochinchinensis. Methods The chemical constituents were isolated and purified by combination of silica gel, macroporous resin, Sephadex LH-20, and ODS ...Objective To study the flavonoids from the heartwood of Dalbergia cochinchinensis. Methods The chemical constituents were isolated and purified by combination of silica gel, macroporous resin, Sephadex LH-20, and ODS column chromatography. Their structures were identified by means of spectral analysis. Results Fifteen flavonoids were isolated and identified as pinocembrin （1）, liquiritigenin （2）, galangin （3）, 7-hydroxy- 6-methoxyflavone （4）, naringenin （5）, alpinetin （6）, 2,3-dimethoxyxanthone （7）, 6,4＇-dihydroxy-7-methoxy-flavan （8）, mucronulatol （9）, 7,8-dihydroxyflavanone （10）, 5,7,3＇,5＇-tetrahydroxyflavanone （11 ）, 4,2＇,5＇-trihydroxy-4＇-methoxychalcone （12）, isoliquiritigenin （13）, butein （14）, and 3＇,5＇,5,7-tetrahydroxy-6-C-I^-D-glucopyranosyl- flavanone （15）, respectively. Conclusion Compounds 7, 8, ｜ 0, and 15 are isolated from the plants of Dalbergia L. f. for the first time, and compounds 1, 3, 5, 6, 9, 11, 12, and 14 are isolated from this plant for the first time.展开更多
基金supported by the Science Innovation Projects of Guangdong Province(grant number 2020KJCX007)Funds for the Central Non-profit Research Institution of Chinese Academy of Forestry(Grant No.CAFYBB2018SZ002)。
文摘Thailand rosewood(Dalbergia cochinchinensis)is a vulnerable high value tree species in subtropical and tropical Southeast Asia.The demand for the rehabilitation of the natural habitat of the species requires high-quality seedlings.However,current fertilizer regimes tend to deliver a coarse rate of fertilizers that result in a low uptake efficiency and a high risk of nutrient excess.Exponential fertilization is an effective approach to promote seedling quality through identifying an optimum dose out of a range of applications.In this study,Thailand rosewood seedlings were cultured in a mixed substrate of perlite,vermiculite,and peat(2:2:3,v/v/v)and received exponential fertilization from 0(control),through 100,200,300,400,and 600 mg nitrogen(N)per plant over a four-month cultural rotation.Height,diameter,and shoot biomass increased with fertilizer rate and were maximized at 300 mg N per plant.This application also reduced nutrient deficiencies and avoided excess supply compared to higher rates.Polysaccharide,proline,and anti-oxidation enzyme activities tended to be greater in unfertilized controls or in over-fertilized high dosages,with lower activities around 100–300 mg N plant(-1).Application of 300 mg N per plant was identified as the optimum dosage as it maximized nutrient reserves,polysaccharide and proline contents,and anti-oxidants without causing any symptoms from excess fertilizer toxicity.Future work is required to identify the effects of N-fixation on the formation of nutritional reserves in Thailand rosewood seedlings subjected to exponential fertilization.
基金National Natural Science Foundation of China(81360629)
文摘Objective To study the flavonoids from the heartwood of Dalbergia cochinchinensis. Methods The chemical constituents were isolated and purified by combination of silica gel, macroporous resin, Sephadex LH-20, and ODS column chromatography. Their structures were identified by means of spectral analysis. Results Fifteen flavonoids were isolated and identified as pinocembrin （1）, liquiritigenin （2）, galangin （3）, 7-hydroxy- 6-methoxyflavone （4）, naringenin （5）, alpinetin （6）, 2,3-dimethoxyxanthone （7）, 6,4＇-dihydroxy-7-methoxy-flavan （8）, mucronulatol （9）, 7,8-dihydroxyflavanone （10）, 5,7,3＇,5＇-tetrahydroxyflavanone （11 ）, 4,2＇,5＇-trihydroxy-4＇-methoxychalcone （12）, isoliquiritigenin （13）, butein （14）, and 3＇,5＇,5,7-tetrahydroxy-6-C-I^-D-glucopyranosyl- flavanone （15）, respectively. Conclusion Compounds 7, 8, ｜ 0, and 15 are isolated from the plants of Dalbergia L. f. for the first time, and compounds 1, 3, 5, 6, 9, 11, 12, and 14 are isolated from this plant for the first time.
