The habanero chili （Capsicum chinense Jacq.） is a species of great demand in the domestic and international markets. One problem in the cultivation is low percentage of seed germination. There is little information ...The habanero chili （Capsicum chinense Jacq.） is a species of great demand in the domestic and international markets. One problem in the cultivation is low percentage of seed germination. There is little information on the use of promoters and imbibition time to increase this parameter, without compromising the quality of seedlings. In this context, authors assessed the independent effect of GAs （gibberellic acid） and KNOs at concentrations of 0, 100, 200, 300, 400 and 500 mg·L1. Seeds without preconditioning were the witness. The experimental unit was a Petri dish with 50 seeds on filter paper placed equidistant. There were three replicates per treatment and the experimental design was randomized complete block. Imbibition time was 24 h. The experimental units were kept in an incubator at 22 ± 2 ℃. From the time of planting and for periods of 24 h for 14 d, experimental units were reviewed to determine the time at the beginning of germination and the total cumulative percentage. The authors also determined the number of normal and abnormal seedlings, the length of hypocotyl and radicle, weight of fresh and dry matter of seedlings. On the fifth day after sowing in vitro, concentrations of 500 mg·L^-1 of GAs, 300 and 400 mg·L^-1 KNO3, increased 208% the percentage of seed germination of habanero chile. On day 14 after sowing in vitro concentrations of 500 mg·L^-1 GA3, 300 and 400 mg·L^-1 KNO3, increased 23% normal seedlings and 40% dry matter thereof, with respect to seeds obtained without preconditioning. Unconditioned seeds before sowing produced 125% more seedlings.展开更多
Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam （Dioscorea spp.） production. Identifying yield- and maturity-related traits and breeding for them w...Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam （Dioscorea spp.） production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits： time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight （tuber yield）, tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. （water yam） on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.展开更多
A greenhouse experiment was conducted to test and compare the suitability of saline compost and saline irrigation water for nutrient status amendment of a slightly productive sandy clay loam soil, to study the macronu...A greenhouse experiment was conducted to test and compare the suitability of saline compost and saline irrigation water for nutrient status amendment of a slightly productive sandy clay loam soil, to study the macronutrient utilization and dry matter production of wheat （Triticum aestivum c.v. Gemmiza 7） grown in a modified soil environment and to determine the effects of compost and saline irrigation water on soil productivity. The sandy clay loam soil was treated with compost of five rates （0, 24, 36, 48, and 60 m3 ha-1, equivalent to 0, 3, 4.5, and 6 g kg-1 soil, respectively） and irrigation water of four salinity levels （0.50 （tap water）, 4.9, 6.3, and 8.7 dS m-l）. The results indicated that at harvest, the electrical conductivity （EC） of the soil was significantly （P 〈 0.05） changed by the compost application as compared to the control. In general, the soil salinity significantly increased with increasing application rates of compost. Soluble salts, K, C1, HCO3, Na, Ca, and Mg, were significantly increased by the compost treatment. Soil sodium adsorption ratio （SAR） was significantly affected by the salinity levels of the irrigation water, and showed a slight response to the compost application. The soil organic carbon content was also significantly （P 〈 0.05） affected by application of compost, with a maximum value of 31.03 g kg-1 recorded at the compost rate of 60 m3 ha-1 and the irrigation water salinity level of 8.7 dS m-1 and a minimum value of 12.05 g kg-1 observed in the control. The compost application produced remarkable increases in wheat shoot dry matter production. The maximum dry matter production （75.11 g pot-1） occurred with 60 ma ha-1 compost and normal irrigation water, with a minimum of 19.83 g pot-1 with no addition of compost and irrigation water at a salinity level of 8.70 dS m-1. Significant increases in wheat shoot contents of K, N, P, Na, and C1 were observed with addition of compost. The relatively high shoot N values may be attributed to increases in N availability in the tested soil caused by the compost application. Similarly, significant increases in the shoot contents of Na and C1 may be ascribed to the increase in soil soluble K and Cl. The increases in shoot P, N, and K contributed to the growth stimulation since P supplied by the compost was probably responsible in saline and alkaline soils where P solubility was very low.展开更多
Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and a...Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and an increase in productivity are a common phenomenon following fertilization in grasslands ecosystem.The magnitude of the response of species diversity and above-ground net primary productivity(ANPP)to fertilization mainly depends on species traits(mean trait values)and traits variability(plasticity).Our aim of this study was to examine(i)changes of species diversity(species richness and Shannon-Wiener index)and ANPP following fertilization;(ii)which species traits or community-weighted mean(CWM)traits can determine ANPP,as expected from the‘biomass ratio hypothesis’;and(iii)the relative role of intra-specific and inter-specific trait variability in this process following fertilization.Methods We measured ANPP and four key plant functional traits:specific leaf area(SLA),leaf dry matter content(LDMC),mature plant height(MPH)and leaf nitrogen concentration(LNC)for 25 component species along a fertilization gradient in an alpine meadow on the Tibetan Plateau.In addition,trait variation of species was assessed using coefficients of variation(CV),and we calculated the ratio of the CVintra to the CVinter.Important Findings Our results showed that:(i)fertilization significantly reduced species richness and Shannon-Weiner diversity index,but sig-nificantly increased ANPP;(ii)there was a significant positive correlation between ANPP and CWM-SLA and CWM-MPH,yet there was no significant relationship between ANPP and CWM-LNC or CWM-LDMC;(iii)intra-specific variability in SLA and MPH was found to be much greater than inter-specific variability,especially at the higher fertilization levels.We con-cluded that CWM-SLA and CWM-MPH can be used to assess the impacts of species changes on ecosystem functioning,and dominant species can maximize resource use through intra-spe-cific variability in SLA and MPH to compensate for the loss of species following fertilization,therefore maintaining high com-munity productivity.展开更多
文摘The habanero chili （Capsicum chinense Jacq.） is a species of great demand in the domestic and international markets. One problem in the cultivation is low percentage of seed germination. There is little information on the use of promoters and imbibition time to increase this parameter, without compromising the quality of seedlings. In this context, authors assessed the independent effect of GAs （gibberellic acid） and KNOs at concentrations of 0, 100, 200, 300, 400 and 500 mg·L1. Seeds without preconditioning were the witness. The experimental unit was a Petri dish with 50 seeds on filter paper placed equidistant. There were three replicates per treatment and the experimental design was randomized complete block. Imbibition time was 24 h. The experimental units were kept in an incubator at 22 ± 2 ℃. From the time of planting and for periods of 24 h for 14 d, experimental units were reviewed to determine the time at the beginning of germination and the total cumulative percentage. The authors also determined the number of normal and abnormal seedlings, the length of hypocotyl and radicle, weight of fresh and dry matter of seedlings. On the fifth day after sowing in vitro, concentrations of 500 mg·L^-1 of GAs, 300 and 400 mg·L^-1 KNO3, increased 208% the percentage of seed germination of habanero chile. On day 14 after sowing in vitro concentrations of 500 mg·L^-1 GA3, 300 and 400 mg·L^-1 KNO3, increased 23% normal seedlings and 40% dry matter thereof, with respect to seeds obtained without preconditioning. Unconditioned seeds before sowing produced 125% more seedlings.
文摘Inadequate yield potential of available varieties and their long growth periods are two of the factors limiting yam （Dioscorea spp.） production. Identifying yield- and maturity-related traits and breeding for them will enhance production. Ten morphological/physiological traits： time of shoot emergence, time of tuber initiation, plant height, shoot dry weight, time of shoot senescence, tuber fresh weight （tuber yield）, tuber number/plant, tuber parenchyma colour, tuber dry matter content and tuber dormancy period were assessed in eight accessions of D. alata L. （water yam） on the field in 2008 and 2009. Tuber yield-related traits were identified as shoot dry weight and time of shoot emergence. Shoot dry weight had the strongest positive effect; time of shoot emergence had a negative effect. High yielding accessions had a high shoot dry weight, but were low in tuber dry matter content. Uniform tuber parenchyma colour was the sole trait related to tuber maturity, but early and late senescing accessions did not consistently differ in the trait. TDa 00/00103 is high yielding and early maturing and may be used as a parent for breeding for high yield and early maturity in D. alata.
文摘A greenhouse experiment was conducted to test and compare the suitability of saline compost and saline irrigation water for nutrient status amendment of a slightly productive sandy clay loam soil, to study the macronutrient utilization and dry matter production of wheat （Triticum aestivum c.v. Gemmiza 7） grown in a modified soil environment and to determine the effects of compost and saline irrigation water on soil productivity. The sandy clay loam soil was treated with compost of five rates （0, 24, 36, 48, and 60 m3 ha-1, equivalent to 0, 3, 4.5, and 6 g kg-1 soil, respectively） and irrigation water of four salinity levels （0.50 （tap water）, 4.9, 6.3, and 8.7 dS m-l）. The results indicated that at harvest, the electrical conductivity （EC） of the soil was significantly （P 〈 0.05） changed by the compost application as compared to the control. In general, the soil salinity significantly increased with increasing application rates of compost. Soluble salts, K, C1, HCO3, Na, Ca, and Mg, were significantly increased by the compost treatment. Soil sodium adsorption ratio （SAR） was significantly affected by the salinity levels of the irrigation water, and showed a slight response to the compost application. The soil organic carbon content was also significantly （P 〈 0.05） affected by application of compost, with a maximum value of 31.03 g kg-1 recorded at the compost rate of 60 m3 ha-1 and the irrigation water salinity level of 8.7 dS m-1 and a minimum value of 12.05 g kg-1 observed in the control. The compost application produced remarkable increases in wheat shoot dry matter production. The maximum dry matter production （75.11 g pot-1） occurred with 60 ma ha-1 compost and normal irrigation water, with a minimum of 19.83 g pot-1 with no addition of compost and irrigation water at a salinity level of 8.70 dS m-1. Significant increases in wheat shoot contents of K, N, P, Na, and C1 were observed with addition of compost. The relatively high shoot N values may be attributed to increases in N availability in the tested soil caused by the compost application. Similarly, significant increases in the shoot contents of Na and C1 may be ascribed to the increase in soil soluble K and Cl. The increases in shoot P, N, and K contributed to the growth stimulation since P supplied by the compost was probably responsible in saline and alkaline soils where P solubility was very low.
基金This study was supported by Natural Science Foundation of China(41230852)Key Program of Chinese Academy of Sciences(KJZD-EW-TZ-G10)+3 种基金Northwest A&F University(Z109021107,Z109021307,QN2013070)West Light Foundation of Chinese Academy of Sciences(K318021305)Natural Science Foundation of Shaanxi Province(2016JQ3008)the China Scholarship Council.
文摘Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and an increase in productivity are a common phenomenon following fertilization in grasslands ecosystem.The magnitude of the response of species diversity and above-ground net primary productivity(ANPP)to fertilization mainly depends on species traits(mean trait values)and traits variability(plasticity).Our aim of this study was to examine(i)changes of species diversity(species richness and Shannon-Wiener index)and ANPP following fertilization;(ii)which species traits or community-weighted mean(CWM)traits can determine ANPP,as expected from the‘biomass ratio hypothesis’;and(iii)the relative role of intra-specific and inter-specific trait variability in this process following fertilization.Methods We measured ANPP and four key plant functional traits:specific leaf area(SLA),leaf dry matter content(LDMC),mature plant height(MPH)and leaf nitrogen concentration(LNC)for 25 component species along a fertilization gradient in an alpine meadow on the Tibetan Plateau.In addition,trait variation of species was assessed using coefficients of variation(CV),and we calculated the ratio of the CVintra to the CVinter.Important Findings Our results showed that:(i)fertilization significantly reduced species richness and Shannon-Weiner diversity index,but sig-nificantly increased ANPP;(ii)there was a significant positive correlation between ANPP and CWM-SLA and CWM-MPH,yet there was no significant relationship between ANPP and CWM-LNC or CWM-LDMC;(iii)intra-specific variability in SLA and MPH was found to be much greater than inter-specific variability,especially at the higher fertilization levels.We con-cluded that CWM-SLA and CWM-MPH can be used to assess the impacts of species changes on ecosystem functioning,and dominant species can maximize resource use through intra-spe-cific variability in SLA and MPH to compensate for the loss of species following fertilization,therefore maintaining high com-munity productivity.
