Effects of exogenous spermidine on the photosynthesis of Cucumis sativus L. seedlings under rhizosphere hypoxia stress     

Tian Wang  Suping Wang  Shirong Guo  Yanjun Sun 《Frontiers of Agriculture in China》2008,2(1):55-60

With water culture, this paper studied the effects of exogenous spermidine (Spd) on the net photosynthetic rate (P _n), intercellular CO₂ concentrations (C _i), stomatal conductance (G _s), transpiration rate (T _r), apparent quantum yield (Φ _c), and carboxylation efficiency (CE) of cucumber seedlings under hypoxia stress. The results showed that P _n decreased gradually under the hypoxia stress, and reached the minimum 10 days later, which was 63.33% of the control. Compared with that of the hypoxia-stressed plants, the P _n 10 days after the application of exogenous Spd increased by 1.25 times. A negative correlation (R ²=0.473−0.7118) was found between _{P n} and C _i, and G _s and T _r changed in wider ranges, which decreased under the hypoxia-stress, but increased under the hypoxia-stress plus exogenous Spd application. There was a significant positive correlation between G _s and T _r (R ²=0.7821−0.9458), but these two parameters had no significant correlation with P _n. The hypoxia stress induced a decrease of Φ _c and CE by 63.01% and 72.33%, respectively, while the hypoxia stress plus exogenous Spd application made Φ _c and CE increase by 23% and 14%, respectively. The photo-inhibition of cucumber seedlings under hypoxia stress was mainly caused by non-stomatal inhibition, while the exogenous Spd alleviating the hypoxia stress by repairing photosynthesis systems. __________ Translated from Chinese Journal of Applied Ecology, 2006, 17(9): 1609–1612 [译自: 应用生态学报]  相似文献   

酸化处理对猪场原水和沼液存储过程中气体排放的影响   总被引：2，自引：1，他引：1  

李路路  董红敏  朱志平  王悦 《农业环境科学学报》2016,35(4):774-784

为探索酸化处理对猪场原水和沼液存储过程中温室气体(CH_4、N_2O、CO_2)以及NH_3排放的影响,采用浓硫酸酸化处理猪场污水,利用动态箱法在线监测存储75 d内各气体排放通量。试验分别设置一个对照组和两个酸化处理组:原水对照组p H为6.5(RCK),加酸处理后p H分别为5.1(RT1)和5.7(RT2);沼液对照组p H为7.8(BCK),加酸处理后p H分别为5.7(BT1)和6.5(BT2)。对于原水组,RCK、RT1、RT2的CH4排放通量分别为32.2、2.37、3.10 g·m~(-3)·d~(-1),N_2O排放通量分别为336.45、23.36、29.79 mg·m~(-3)·d~(-1),NH_3排放通量分别为1.01、0.82、1.63 g·m~(-3)·d~(-1),CO2排放通量分别为109.14、99.66、110.55 g·m~(-3)·d~(-1),酸化处理显著降低原水CH_4和N_2O排放量;对于沼液组,BCK、BT1、BT2的CH_4排放通量分别为0.24、0.86、0.63 g·m~(-3)·d~(-1),N_2O排放通量分别为2.54、73.43、268.66mg·m~(-3)·d~(-1),NH_3排放通量分别为8.02、1.35、1.51 g·m~(-3)·d~(-1),CO_2排放通量分别为48.9、44.3、44.0 g·m~(-3)·d~(-1),酸化沼液显著增加CH_4和N_2O排放通量,但NH3排放可显著降低81%~83%,同时酸化组内氨氮含量较对照组增加40%~54%。根据CH_4和N_2O在100年尺度上的全球增温潜势计算各组的综合温室效应,猪场原水酸化后CO_2-eq降低91%~92%,沼液酸化后温室气体增加5~11倍。结果表明:酸化处理原水能够有效降低温室气体排放,而酸化处理沼液则一定程度上增加了温室气体排放,但可有效降低NH_3排放,同时保留沼液中氮养分。  相似文献   

不同品种授粉对‘轮台白杏’坐果及果实品质的影响          下载免费PDF全文

安晓芹  廖康  孙慧瑛  刘娟  李永闲  廖小龙  王云 《浙江农林大学学报》2013,30(2):187-193

 以‘轮台白杏’Armeniaca vulgaris ‘Luntaibaixing’与26个新疆杏品种进行正反交,探讨不同品种授粉对‘轮台白杏’坐果及果实品质的影响。结果表明：不同品种授粉均提高了‘轮台白杏’坐果率,以‘卡巴克胡安娜’‘Kabakehuanna’,‘伊犁阿克玉吕克’‘Yiliakeyulvke’,‘特尔湾玉吕克’‘Teerwanyulvke’等品种效果为佳,但反交中经‘轮台白杏’授粉,仅有‘库车白杏’‘Kuchebaixing’等8个品种的坐果率有所增加,其余品种坐果率则低于自然授粉;与自然授粉所得果实比较,‘轮台白杏’的单果质量、果核质量以及可溶性固形物、维生素C、可滴定酸、总糖均受授粉品种影响,其中‘早熟胡安娜’‘Zaoshuhuanna’,‘阿克达拉孜’‘Akedalazi’,‘阿克阿依’‘Akeayi’等品种授粉后果实维生素C极显著降低（P＜0.01）,‘阿克阿依’,‘贾格达玛依桑’‘Jiagedamayisang’,‘米录’‘Milu’等品种授粉后可滴定酸极显著提高（P＜0.01）;果形指数受授粉品种影响较少,仅‘库车白杏’,‘卡拉胡安娜’‘Kalahuanna’授粉对‘轮台白杏’果形指数有极显著影响,‘大果胡安娜’‘Daguohuanna’等5个品种授粉为显著降低（P＜0.05）;综合坐果率考虑,‘卡巴克胡安娜’,‘早熟胡安娜’,‘伊犁阿克玉吕克’适于做‘轮台白杏’授粉树。不同品种授粉对‘轮台白杏’坐果及果实品质存在效果差异,生产中可根据需要选择父本提高坐果率和改善果实品质。表5参10  相似文献   

华北驼绒藜和四翅滨藜对干旱胁迫的生理反应     

席艳丽  蔡进军  刘统高  许浩  董立国  马璠  李生宝 《西北农业学报》2017,(5):790-796

为研究引种小灌木在干旱胁迫下的生理光合特性,以1a生华北驼绒藜、四翅滨藜2种扦插苗为试验材料,研究土壤水分[土壤水分为田间持水量的85%~90%(CK)、65%~70%(T_1)、50%~55%(T_2)和35%~40%(T_3)]对2种灌木光合生理指标的影响。结果表明:随着水分胁迫程度的增加,2种灌木根冠比、电解质外渗率呈现CKT_1T_2T_3的变化规律;丙二醛质量摩尔浓度与CK相比,各水平下均显著增加,且都在T_2水平下达最大;过氧化物酶活性在T_1水平下达到最大,分别为340.83U·mg~(-1)·min~(-1)、862.93U·mg~(-1)·min~(-1);在T_2水平下,四翅滨藜脯氨酸质量分数较CK增加28倍;华北驼绒藜叶片蒸腾速率(T_r)、净光合速率(P_n)均呈现出CKT_1T_2T_3的变化特征;在T_1水平下,四翅滨藜叶绿体色素(叶绿素a、叶绿素b及类胡萝卜素)增加,光合能力增强。  相似文献   

Effect of cell mediated immunity regulation of duck enhanced by duck IFN-α eukaryon expression plasmid and inoculated with DPV attenuated vaccine by gene-gun     

Zhiping Cheng  Anchun Cheng  Mingshu Wang  Bin Chen  Chuang Liu  Kun Duan  Xue Zhou  Xiaoyue Chen 《Frontiers of Agriculture in China》2008,2(3):343-347

In order to study the effect of cell mediated immunity regulation of duck IFN-α eukaryon expression plasmid (pcDNA-SDIFN-α) on duck plague virus (DPV) attenuated vaccine in ducks, pcDNA-SDIFN-α was administered to 28-day-old ducks at doses of 1, 3 and 6 μg per duck, respectively, by gene-gun. PBS and empty vector pcDNA were used as control. Fifteen days later, all ducks were injected with DPV attenuated vaccine and blood samples were collected at 3, 7, 14, 21, 28, 35, 49, 63 and 84 days after injection. T-lymphocyte proliferation tests (MTT) were used to detect the T-lymphocyte proliferation in the peripheral blood (PBL) of ducks. Blood samples collected at 7, 14, 21, 28, 35 and 49 days after injection were detected by fluorescence-activated cell sorter (FACS) for recording the number of CD₃ ⁺ T-lymphocytes of ducks. Results were as follows: (1) Reaction of T-lymphocytes in PBL to ConA (OD value) of ducks treated with pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 3–84 days. There were highly significant differences between the 1 μg per duck group and the two control groups in 3–84 days (P ⩽ (0.01), between the 3 μg per duck group and the two control groups in 3–84 days (P ⩽ 0.01, P ⩽ 0.05), and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). The significant difference was also present between the groups of 1, 3 and 6 μg per duck in 3–35 days (P ⩽ 0.05). However, there was no significant difference between the 3 and 6 μg per duck groups (P ⩾ 0.05). The pcDNA control group was higher than PBS control group, but no difference was detected (P ⩾ 0.05). (2) Change of the number of CD₃ ⁺ T-lymphocytes in ducks administered with different doses of pcDNA-SDIFN-α was higher than that of PBS and pcDNA control groups in 7–49 days. The change in the 1 μg per duck group was significantly higher than that in PBS and pcDNA control groups in 14–49 days (P ⩽ 0.01). There were significant differences between the 3 μg per duck group and the two control groups in 21–49 days (P ⩽ 0.01, P ⩽ 0.05) and between the 6 μg per duck group and the two control groups in 7–49 days (P ⩽ 0.01, P ⩽ 0.05). However, no significant differences among the groups of 1, 3, and 6 μg per duck groups (P ⩾ 0.05) and between the two control groups (P ⩾ 0.05) were found. The results indicated that pcDNA-SDIFN-α administered 15 days before injection of DPV-attenuated vaccine could significantly enhance cellular immunity induced by DPV-attenuated vaccine. pcDNA-SDIFN-α is an excellent DPV-attenuated vaccine molecular adjuvant and the best result can be obtained with the dose of 1 μg per duck of pcDNA-SDIFN-α inoculated by gene-gun. __________ Translated from Acta Veterinaria et Zootechnica Sinica, 2007, 38 (10): 1066–1071 [译自: 畜牧兽医学报]  相似文献   

油菜抗倒伏测试风洞关键部件仿真与试验          下载免费PDF全文

王浩杰  任奕林  邢博源  黄秋航  王琦龙  王建松 《华中农业大学学报》2024,43(1):232-241

为解决现有油菜抗倒伏品种选育周期长、难度大等问题，依托计算流体力学软件Fluent建立油菜抗倒伏测试风洞模型，对风洞扩散段、稳定段、收缩段等关键部位进行参数设计及仿真试验，分析该模型对风洞流场品质的影响，最终通过正交试验选择最佳设计方案。结果显示，单因素试验中，收缩段长度Lc增加，风洞出口风速变异系数增加，气流品质下降；随稳定段长度Lw增加，风洞出口风速变异系数先减小后增加，稳定段长度1 000 mm时，风速变异系数最低，气流品质最佳；阻尼网距稳定段出口长度增加，风洞出口风速变异系数先降低后增加，阻尼网距稳定段出口0.65Lw时，风速变异系数最小。正交试验结果显示，收缩段长度600 mm、稳定段800 mm、阻尼网距风洞出口0.65Lw时，对应风洞试验区风速平均变异系数为0.139，风速较其他方案更稳定，气流品质最佳。实测验证发现，与仿真结果相比，实测风速大小无明显差别，且实测结果中各截面风速变异系数略优于仿真值，整体仿真结果与实测效果拟合较好。  相似文献