叶面喷施抗蒸剂对苹果树水分状态的影响

研究了叶面喷施抗蒸剂对盆栽苹果水分状态的影响。结果表明：抗旱剂一号（主要成分为黄腐酸）可明显降低树体蒸腾（最低时为对照的３９．２１％）、提高气孔阻力（最大时为对照的２４３．９６％）和叶片水势（一般比对照提高０．２－０．４ＭＰａ、最大０．７ＭＰａ），并对叶温未产生明显的影响（变化一般小于１℃），有效作用期长达１５ｄ以上。在果树旱期喷施，可明显改善树体水分状态。腐殖酸效果不明显。     

Effect of water deficit in different growth stages on stem sap flux of greenhouse grown pear-jujube tree

The effects of water deficit in different fruit growth stages on the variation of stem sap flux of 6-year old greenhouse-grown pear-jujube trees were investigated. Treatments included sufficient water supply during the whole fruit-growing period (T₁), mild water deficit during the flowering–fruit setting stage (T₂), moderate water deficit during the fruit rapid growth stage (T₃) and severe water deficit during the fruit maturing stage (T₄). Results showed that significant compensation effect on stem sap flux after re-watering was observed in T₂, but not in T₃ and T₄ stages. At the end of rapid growth stage, the diurnal variation of stomatal conductance generally had a similar trend as that of stem sap flux, but with a distinct midday depression from 12:00 to 14:00 p.m. In addition, a linear relationship between the relative available soil water content (RAWC) and the ratio of daily stem sap flux to that of sufficient water treatment was observed (R² = 0.4489).     

Response of Vitis vinifera cv. ‘Tempranillo’ to partial rootzone drying in the field: Water relations, growth, yield and fruit and wine quality

This paper reports the effects of irrigation amount and partial rootzone drying (PRD) on water relations, growth, yield and wine quality of Vitis vinifera cv. ‘Tempranillo’ during two consecutive years in a commercial vineyard with a deep, light-clay soil located in Requena, Valencia, Spain. Partial rootzone drying applied at two amounts (100% and 50% of the estimated crop evapotranspiration), was compared to conventional drip irrigation, and also to rainfed vines. Results showed that the effects of irrigation amount on yield and wine quality were different between years. In 2003 with low yield values (around 6.3 t ha⁻¹) irrigation did neither affect grape production nor wine quality. However, in the following year, with much higher general yield (17 t ha⁻¹), the high irrigation dose increased yield by 30% compared to rainfed vines and it also increased must total soluble solids and wine alcohol content. In both seasons, PRD did not significantly affect physiological parameters, nor growth, yield or fruit and wine quality, when compared to the same amount of water applied by conventional drip irrigation. Overall these results suggest that, under our experimental conditions, it was the irrigation amount rather than the system of application what affected vine performance, indicating the difficulties of successfully employing the PRD type of irrigation with a drip system in heavy and deep soils.     

大气CO2浓度升高对茶树光合生理特性的影响

通过对不同大气CO2浓度水平下的茶树观测试验,研究了大气CO2增长对茶树新梢叶片净光合速率、蒸腾气孔导度、水分利用效率、叶绿素含量和营养元素含量等光合生理特性的影响。结果表明,在大气CO2浓度为550、750μmol·mol-1时,比正常大气CO2水平下茶树叶片日平均净光合速率提高17.9%和25.8%,并缓解和消除了光合午休现象;茶树叶片气孔导度降低7.6%和13.0%,蒸腾速度稍有下降,水分利用效率提高21.6%和35.8%;同时使茶树新梢叶绿素a、叶绿素b、叶绿素总量和类胡萝卜素含量分别提高12.8%～18.4%、14.0%～22.0%、13.1%～19.4%和17.2%～20.1%,但叶绿素a与叶绿素b的比值有所降低。大气CO2浓度的升高使新梢营养元素N、K、Ca含量有不同程度降低,而Mg、Fe、Zn、Mn、Cu含量有所增加。     

刺槐光合生理生态特性日变化研究

为了解刺槐光合生理生态特性及生长的适宜生态条件,培育出优质高产的林木,采用LI-6400光合测定系统对刺槐的光合生理特性日变化及其与气象因子关系进行了研究。结果表：（1）刺槐的Pn日变化呈“双峰型”曲线,有明显的“午休”现象,第一个峰出现在9：00左右,第二个峰出现在15：00左右,第一个峰值明显高于第二个峰值。（2）Tr在很大程度上决定于气孔的活动状态,Ci因为Gs的降低而减少,刺槐的光合速率控制因子为气孔限制。（3）Pn与Gs成极显著正相关,与Tr成显著性正相关。环境因子主要是影响叶片的Tr、Vpdl和Tl来影响Pn,PAR对Pn的影响较大,但可能不是导致刺槐光合“午休”的直接因素。     

燕麦叶片光合速率、气孔导度对光强和CO_2的响应与模拟

为指导燕麦生产,并了解燕麦在陆地生态系统水-碳循环过程中的作用,用LI-6400便携式光合测定仪,人工控制光强和CO2浓度,在锡林郭勒盟对燕麦叶片光合速率、气孔导度进行了研究,结果表明:燕麦叶片光合速率随光强的增强而增大,可以用米氏方程对其进行描述,在自然CO2浓度下,燕麦叶片的潜在最大光合速率为18.63μmol/(m2·s);在饱和光强下,光合速率随CO2浓度的增大而增大,也可以用米氏方程对其进行描述,CO2浓度→∞时,潜在最大光合速率达到110.28 μmol/(m2·s);气孔导度随光强的增强而增大,随CO2浓度的增大而减小;气孔限制值随光强的增强而增大,气孔限制值随CO2浓度的增大迅速增大,而[CO2]>200 μmol/mol时,气孔限制值基本保持恒定.     

不同天气条件下田间大豆光合作用日变化的研究

田间大豆叶片光合速率的日变化进程和光合午休的有无、轻重,在不同天气条件下表现不同,并无固定模式。高湿的晴天,没有光合午休,气孔因素和叶肉因素对光合的限制都很小;高湿适温的多云天气,光合速率主要受光强制约,光强高时,光合速率受气孔因素限制,光强低时,受叶肉因素限制;低湿高温的晴天,常有午休出现,光合速率的中午降低,主要是气孔因素限制的结果,有时也出现叶肉因素限制。诱发气孔限制的生理生态因子,首先是空气相对湿度（RH）和叶片、大气间水汽压差（VPD）,其次是叶温（LT）和叶片相对含水量（RWC）。     

Role of miR-219 and TGFBR2 in pathogenesis of renal fibrosis

AIM:To study the role of microRNA-219 (miR-219) in regulation of transforming growth factor-β receptor type 2 (TGFBR2) in renal fibrosis. METHODS:The renal fibrosis patients (n=70) were selected in this stu-dy, and 20 cases of healthy people were selected as control group. RT-qPCR was used to detect the expression of miR-219 in the serum of the patients with renal fibrosis and control group, and the expression of miR-219 in NRK49F cells after stimulation with angiotensin Ⅱ(AngⅡ) was detected. The protein expression of α-smooth muscle actin (α-SMA) in the NRK49F cells transfected with miR-219 mimics after stimulation with AngⅡ was determined by Western blot. The potential target gene TGFBR2 of miR-219 was screened and verified by the method of luciferase reporter gene. RT-qPCR and Western blot were used to detected the effect of miR-219 mimics on the expression of TGFBR2 at mRNA and protein levels, and the mRNA expression of α-SMA, connective tissue growth factor (CTGF), type I collagen α1 (COL1A1) and COL3A1 in the NRK49F cells was also detected, respectively. The unilateral ureteral occlusion (UUO) mouse model was established and the expression of miR-219 in the renal tissue was monitored. The morphological change of renal fibrosis was observed in the UUO mice after injection of miR-219, and the mRNA expression levels of COL1A1 and COL3A1 were detected. RESULTS:The expression level of miR-219 in the patients with renal fibrosis was significantly lower than that in control group, and the expression of miR-219 in the UUO mice was decreased significantly (P<0.01). The expression level of miR-219 was significantly decreased in the NRK49F cells after AngⅡ stimulation, and miR-219 mimics inhibited the protein expression of α-SMA(P<0.01). miR-219 mimics had a targeted regulatory effect on TGFBR2 gene, which inhibited the mRNA and protein expression of TGFBR2. miR-219 mimics inhibited the mRNA expression of α-SMA, CTGF, COL1A1 and COL3A1. miR-219 also down-regulated the mRNA expression of COL1A1 and COL3A1 in the UUO mice and inhibited the process of renal fibrosis. CONCLUSION:miR-219 inhibits the development of renal fibrosis by inhibiting the expression of TGFBR2, which may become a new target for the diagnosis and treatment of renal fibrosis.     

直立型扁蓿豆对干旱胁迫和复水的响应及适应策略

以直立型扁蓿豆[Medicago ruthenica（L.）Sojak.cv.Zhilixing]为材料,于苗期连续干旱处理12 d后复水4 d,研究直立型扁蓿豆幼苗形态结构特征、生理代谢及生物量分配对干旱胁迫及复水的响应,揭示直立型扁蓿豆对干旱胁迫及复水的适应策略。结果表明：随着干旱胁迫时间延长,直立型扁蓿豆叶片气孔开放率逐渐降低,处理9 d后气孔及表皮细胞密度比正常浇水处理（CK）分别增加48.5%和36.6%,形成小而密的表皮细胞和气孔。生理上,除MDA含量随胁迫时间的延长逐渐增加外,其余指标均先升高后降低,干旱胁迫9 d时达最高,SOD、POD、叶绿素、可溶性糖、可溶性蛋白及脯氨酸分别较CK提高88.9%、111.2%、86.7%、140.5%、147.8%和124.6%。同时,生物量随胁迫时间的延长先增大后减小,于干旱胁迫9 d达最大值,比CK增加16.4%,总的分配格局表现出地上生物量投资高于地下,地下生物量投资比例随胁迫时间的延长逐渐增加,而地上生物量变化与其相反。复水后各指标均能恢复至CK水平或超过CK,表现出极强的复水敏感性和潜在恢复能力。该品种扁蓿豆对干旱胁迫及复水的适应主要分为3个时期：主动适应期,其生理参数的可塑性指数为形态参数的1.33倍,主要通过抗氧化及渗透调节来减少水分散失增加水分吸收、缓解氧化伤害以适应干旱逆境;被动适应期,其形态参数的可塑性指数为生理参数的1.31倍,主要采用牺牲生物量的生存策略以及降低色素含量减少光吸收的光保护机制来提高逆境下的生存能力;复水恢复期,根冠比、气孔开放率、气孔及表皮细胞密度比CK分别增加25.9%、29.7%、24.2%和16.3%,其较高的根冠比和叶片较高的气孔开放率及小而密的气孔及表皮细胞特征,保证了直立型扁蓿豆吸水能力以及水分运输效率的迅速恢复。综上,直立型扁蓿豆抗旱能力较强,能够通过形态生理的改变以及调整不同器官的生物量分配来应对与适应干旱逆境及复水,且在不同处理阶段采取不同的适应策略以达到生存目的。     

水稻根系与叶片光合特性的关系

 【目的】揭示水稻根系与叶片光合特性之间的联系。【方法】在水培条件下以水稻幼苗为材料，研究不同剪根方式对水稻叶片光合速率、气孔导度和蒸腾速率的影响效应。【结果】剪除全部根系后，顶一叶叶片的光合速率、气孔导度和蒸腾速率分别立即平均下降10.25％、53.99％和46.26％。剪除一半根系时，顶一、二叶的光合速率比断根前分别下降0.05％和8.51％，气孔导度分别下降24.03％和35.80％，蒸腾速率分别下降21.22%和30.93%；进一步剪除剩余全部根系时，顶一、二叶的光合速率比断根前分别下降12.57％和17.22％，气孔导度分别下降55.86％和61.84％，蒸腾速率分别下降50.96％、55.96％。【结论】根系与地上部叶片光合特性间存在密切的直接关系。