Endogenous hormones play an important role in the growth and development of roots. The objective of this research was to study the effect of four types of N fertilizers on the root growth of strawberry (Fragaria anana...Endogenous hormones play an important role in the growth and development of roots. The objective of this research was to study the effect of four types of N fertilizers on the root growth of strawberry (Fragaria ananassa Duchesne) and the endogenous enzymes of indole-3-acetic acid (IAA), abscisic acid (ABA), and isopentenyl adenosine (iPA) in its roots and leaves using enzyme-linked immunosorbent assay. Application of all types of N fertilizers significantly depressed (P ≤ 0.05) root growth at 20 d after transplanting. Application of organic-inorganic fertilizer (OIF) as basal fertilizer had a significant negative effect (P ≤ 0.05) on root growth. The application of OIF and urea lowered the lateral root frequency in strawberry plants at 60 d (P ≤ 0.05) compared with the application of two organic fertilizers (OFA and OFB) and the control (CK). With the fertilizer treatments, there were the same concentrations of IAA and ABA in both roots and leaves at the initial growth stage (20 d), lower levels of IAA and ABA at the later stage (60 d), and higher iPA levels at all seedling stages as compared to those of CK. Thus, changes in the concentrations of endogenous phytohormones in strawberry plants could be responsible for the morphological changes of roots due to fertilization.展开更多
Fusarium wilt is one of the most serious diseases of banana plants caused by soil-borne pathogen Fusarium oxysporum f.sp. cubense(FOC). In this study a pot experiment was conducted to evaluate the effects of different...Fusarium wilt is one of the most serious diseases of banana plants caused by soil-borne pathogen Fusarium oxysporum f.sp. cubense(FOC). In this study a pot experiment was conducted to evaluate the effects of different bio-organic fertilizers(BIOs) on Fusarium wilt of banana, including the investigations of disease incidence, chitinase and β-1,3-glucanase activities of banana plants, and FOC populations as well as soil rhizosphere microbial community. Five fertilization treatments were considered, including chemical fertilizer containing the same N, P and K concentrations as the BIO(control), and matured compost mixed with antagonists Paenibacillus polymyxa SQR-21 and Trichoderma harzianum T37(BIO1), Bacillus amyloliquefaciens N6(BIO2), Bacillus subtilis N11(BIO3), and the combination of N6 and N11(BIO4). The results indicated that the application of BIOs significantly decreased the incidence rate of Fusarium wilt by up to 80% compared with the control. BIOs also significantly promoted plant growth, and increased chitinase andβ-1,3-glucanase activities by 55%–65% and 17.3%–120.1%, respectively, in the banana roots. The population of FOC in the rhizosphere soil was decreased significantly to about 104 colony forming units g-1with treatment of BIOs. Serial dilution plating and denaturing gradient gel electrophoresis analysis revealed that the application of BIOs increased the densities of bacteria and actinomycetes but decreased the number of fungi in the rhizosphere soil. In general, the application of BIOs revealed a great potential for the control of Fusarium wilt disease of banana plants.展开更多
Background The percutaneous transcatheter closure of secundum atrial septal defect (ASD) is increasingly a widespread alternative to surgical closure.The aim of this study was to assess long-term results of percutan...Background The percutaneous transcatheter closure of secundum atrial septal defect (ASD) is increasingly a widespread alternative to surgical closure.The aim of this study was to assess long-term results of percutaneous closure of secundum-type atrial septal defect (ASD Ⅱ).Methods Between January 2001 and December 2005,61 patients underwent a successful percutaneous closure of ASD Ⅱ; including 25 male and 36 female.All were included in the patient study and were followed up to monitor by electrocardiogram and echocardiography,at intervals of 3 days,3 months,6 months,1 year,2 years,and 5 years after operation.Results Three days after percutaneous transcatheter septal closure (PTSC),the right atrium diameter,right ventricular end-diastolic left-right diameter and right ventricutar end-diastolic volume (RVEDV) decreased significantly (P 〈0.05).Right ventricular end-diastolic anteroposterior diameter (RVEDD),right ventricular end-systolic volume (RVESV) and right ventricular ejection fraction (RVEF) also decreased (P〈0.01).During the period from 3 to 6 months,the size of the right atrium and right ventricle returned to normal range.Three days after PTSC,the left ventricular end-diastolic diameter (LVEDD),left ventricular end-diastolic volume (LVEDV),left ventricular end-systolic volume (LVESV),left ventricular-systolic volume (LVSV) and left ventricular ejection fraction (LVEF) were significantly increased (P 〈0.05).At 1 year,the size of the left atrium,left ventricle and left cardiac function returned to normal range (P 〈0.01).There were no deaths or significant complications during the study.At five year follow-up,all defects were completely closed and remained closed thereafter.Conclusion Transcatheter closure of ASD Ⅱ effectively eliminated the abnormal shunt and,subsequently improved the dimensions of each chamber and cardiac function.展开更多
基金supported by the National High Technology Research and Development Program (863 Program) of China(No.2004AA246080)the Program for the Development of High-Tech Industries from the Education Department ofJiangsu Province, China.
文摘Endogenous hormones play an important role in the growth and development of roots. The objective of this research was to study the effect of four types of N fertilizers on the root growth of strawberry (Fragaria ananassa Duchesne) and the endogenous enzymes of indole-3-acetic acid (IAA), abscisic acid (ABA), and isopentenyl adenosine (iPA) in its roots and leaves using enzyme-linked immunosorbent assay. Application of all types of N fertilizers significantly depressed (P ≤ 0.05) root growth at 20 d after transplanting. Application of organic-inorganic fertilizer (OIF) as basal fertilizer had a significant negative effect (P ≤ 0.05) on root growth. The application of OIF and urea lowered the lateral root frequency in strawberry plants at 60 d (P ≤ 0.05) compared with the application of two organic fertilizers (OFA and OFB) and the control (CK). With the fertilizer treatments, there were the same concentrations of IAA and ABA in both roots and leaves at the initial growth stage (20 d), lower levels of IAA and ABA at the later stage (60 d), and higher iPA levels at all seedling stages as compared to those of CK. Thus, changes in the concentrations of endogenous phytohormones in strawberry plants could be responsible for the morphological changes of roots due to fertilization.
基金Supported by the National High Technology Research and Development Program(863 Program)of China(No.2010AA10Z401)
文摘Fusarium wilt is one of the most serious diseases of banana plants caused by soil-borne pathogen Fusarium oxysporum f.sp. cubense(FOC). In this study a pot experiment was conducted to evaluate the effects of different bio-organic fertilizers(BIOs) on Fusarium wilt of banana, including the investigations of disease incidence, chitinase and β-1,3-glucanase activities of banana plants, and FOC populations as well as soil rhizosphere microbial community. Five fertilization treatments were considered, including chemical fertilizer containing the same N, P and K concentrations as the BIO(control), and matured compost mixed with antagonists Paenibacillus polymyxa SQR-21 and Trichoderma harzianum T37(BIO1), Bacillus amyloliquefaciens N6(BIO2), Bacillus subtilis N11(BIO3), and the combination of N6 and N11(BIO4). The results indicated that the application of BIOs significantly decreased the incidence rate of Fusarium wilt by up to 80% compared with the control. BIOs also significantly promoted plant growth, and increased chitinase andβ-1,3-glucanase activities by 55%–65% and 17.3%–120.1%, respectively, in the banana roots. The population of FOC in the rhizosphere soil was decreased significantly to about 104 colony forming units g-1with treatment of BIOs. Serial dilution plating and denaturing gradient gel electrophoresis analysis revealed that the application of BIOs increased the densities of bacteria and actinomycetes but decreased the number of fungi in the rhizosphere soil. In general, the application of BIOs revealed a great potential for the control of Fusarium wilt disease of banana plants.
文摘Background The percutaneous transcatheter closure of secundum atrial septal defect (ASD) is increasingly a widespread alternative to surgical closure.The aim of this study was to assess long-term results of percutaneous closure of secundum-type atrial septal defect (ASD Ⅱ).Methods Between January 2001 and December 2005,61 patients underwent a successful percutaneous closure of ASD Ⅱ; including 25 male and 36 female.All were included in the patient study and were followed up to monitor by electrocardiogram and echocardiography,at intervals of 3 days,3 months,6 months,1 year,2 years,and 5 years after operation.Results Three days after percutaneous transcatheter septal closure (PTSC),the right atrium diameter,right ventricular end-diastolic left-right diameter and right ventricutar end-diastolic volume (RVEDV) decreased significantly (P 〈0.05).Right ventricular end-diastolic anteroposterior diameter (RVEDD),right ventricular end-systolic volume (RVESV) and right ventricular ejection fraction (RVEF) also decreased (P〈0.01).During the period from 3 to 6 months,the size of the right atrium and right ventricle returned to normal range.Three days after PTSC,the left ventricular end-diastolic diameter (LVEDD),left ventricular end-diastolic volume (LVEDV),left ventricular end-systolic volume (LVESV),left ventricular-systolic volume (LVSV) and left ventricular ejection fraction (LVEF) were significantly increased (P 〈0.05).At 1 year,the size of the left atrium,left ventricle and left cardiac function returned to normal range (P 〈0.01).There were no deaths or significant complications during the study.At five year follow-up,all defects were completely closed and remained closed thereafter.Conclusion Transcatheter closure of ASD Ⅱ effectively eliminated the abnormal shunt and,subsequently improved the dimensions of each chamber and cardiac function.