喀斯特地区野生毛葡萄的钙组分特征及其对高钙环境的适应性分析

为了探究喀斯特地区野生毛葡萄(Vitis quinquangularis Rehd.)器官的钙含量、组分及其分布特征,揭示野生毛葡萄的需钙特性及其对高钙土壤的适应机制。该研究以贵州喀斯特地区野生毛葡萄为材料,取样测定了40个样地的野生毛葡萄立地土壤的pH值、交换性钙含量及其根、茎、叶中钙和镁及其钙组分含量,分析土壤交换性钙含量与不同钙组分间的关系,并观察野生毛葡萄叶片表面及根、茎、叶中的钙晶体。结果表明:(1)喀斯特地区野生毛葡萄总钙含量在器官中的分布表现为叶>根>茎,其分布特征与喜钙植物类似。(2)野生毛葡萄根、茎、叶中主要钙组分含量由高到低依次基本为草酸钙、果胶酸钙、水溶性钙、磷酸钙+碳酸钙、硝酸钙+氯化钙、硅酸钙(茎中稍有不同),根、茎、叶中草酸钙占所有钙组分总量和总钙含量的比例均最高,其次是果胶酸钙。(3)各样地野生毛葡萄叶片中Ca+Mg的含量范围在1.30%~4.07%之间,绝大多数在3.0%~4.0%范围内,表现出喜钙植物叶中高Ca+Mg含量的特性。(4)在喀斯特地区的野生毛葡萄体内,多种钙组分含量与土壤中的钙含量呈显著或极显著的正相关关系。(5)扫描电镜观察发现,野生毛葡萄叶片和根中储存有大量的草酸钙晶体,叶片中的草酸钙可通过气孔排出体外。研究发现,喀斯特地区野生毛葡萄属于喜钙植物,对喀斯特高钙环境的适应性强,叶片中钙的富集量大,有大量的草酸钙和果胶酸钙储存于体内,这种储钙特性和气孔的排钙行为对野生毛葡萄适应高钙环境具有重要作用。

不同钙环境下植物几种抗逆境指标的对比研究

本文选取贵州茂兰自然保护区中只生长在岩溶区石灰土上的嗜钙植物6种、只生长在非岩溶区红黄壤上的嫌钙植物7种,以及2种土壤上都能生长良好的中间型植物7种,分析其根际土钙全量及植物叶片3种抗逆性指标,结果显示:(1)嗜钙植物根际土钙全量、叶片脯氨酸(Pro)含量、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性的变化分别为w(Ca)=32.44～43.98g/kg、w(Pro)=97.53～183.62μg/g、6.21～38.43μKat及1.47～2.48μKat,略高于中间型植物,高出嫌钙植物1～2个数量级;(2)大部分嗜钙植物通过提高Pro含量及SOD、POD活性等保护性物质稳定膜的透性,将高浓度的钙阻隔在原生质外;而中间型植物主要通过控制根系吸收或地下部分向地上部分的运移来减少植物体内的钙。

Calcium Addition Affects Germination and Early Seedling Growth of Sweet Sorghum under Saline Conditions

[Objective] This study aimed to determine the interactive effects of supple- mental Ca amendment and salinity on germination of sweet sorghum seeds in saline solution culture medium, and investigate the effects of different combinations of Na/Ca ratio in saline soils on the early growth of sweet sorghum plants. [Method] A germi- nation test and a greenhouse pot experiment were conducted to assess the interac- tive effects of calcium addition to culture medium on the germination and seedling growth of sweet sorghum （Sorghum saccharatum Moench） in saline soils with a range of NaYCa ratios. In the germination test, seeds were treated with different combinations of five calcium levels [0, 5, 10, 15, and 20 mmol/L Ca（NO3）2] and five salinity levels （0, 50, 100, 150, and 200 mmol/L NaCI）. In the greenhouse experi- ment, seeds were sown in potting soils containing 3 salinity levels （2.3, 4.7 and 7.0 dS/m） and three Na：Ca ratios （10：0, 10：1, and 5：1）. [Result] In the germination test, Ca addition at 5 mmol/L promoted germination by 5.5%, 9.9%, and 17.0% at the 3.4, 6.7 and 10.1 dS/m salinity levels. The higher Ca level （10 mmol/L） also in- creased germination by 9.1% and 7.8% at the 3.4 and 6.7 dS/m salinity levels. Then even higher Ca addition at 15 and 20 mmol/L appeared to promote germina- tion when culture media had high salinity （10.1 and 13.4 dS/m）. In the greenhouse pot experiment, saline soil amended with supplemental Ca at the 2.3 and 4.7 dS/m salinity levels significantly promoted early seedling growth, with an increase of 6.8% to 28.2% in plant height and 14.3% to 67.9% in whole plant weight. From 28 to 42 d after seeding, the relative growth of seedling was increased by Ca addition, with a reduction of 49.5% to 66.0% in plant height and 4.8% to 61.9% in whole plant weight. From 42 to 56 d after seeding, however, the relative growth of seedling was significantly inhibited by Ca amendment. [Conclusion] Results of this study indicate that appropriate supplemental Ca could improve sorghum germination and early seedling growth in saline soils.

外翻肠囊法考察盐酸小檗胺对盐酸小檗碱肠吸收特性的影响

目的:研究正常环境和高钙环境下,大鼠不同肠段中盐酸小檗胺对盐酸小檗碱肠吸收特性的影响。方法:采用大鼠外翻肠囊模型,通过HPLC检测不同配伍组外翻肠囊吸收液中盐酸小檗碱的含量,对不同配伍组的单位面积吸收量进行单因素方差分析。结果:与相同时间点正常J70组(正常环境,盐酸小檗碱质量浓度70 mg·L-1)比较,120 min时正常J70+Ver100组(正常环境,盐酸小檗碱质量浓度70 mg·L-1,加入盐酸维拉帕米质量浓度100 mg·L-1)的单位面积吸收量在回肠段显著增加(P<0.05);30,60,90 min时高钙J70+A35组(高钙环境,盐酸小檗碱质量浓度70 mg·L-1,加入盐酸小檗胺质量浓度35 mg·L-1)在十二指肠的单位面积吸收量显著增加(P<0.05);30,90,120 min时高钙J70+A70组(高钙环境,盐酸小檗碱质量浓度70 mg·L-1,加入盐酸小檗胺质量浓度70 mg·L-1)在回肠的单位面积吸收量显著增加(P<0.05)。相较于相同质量浓度的正常组,高钙J70+A35组、高钙J70+A70组中盐酸小檗碱的肠吸收更好。结论:盐酸小檗胺在一定程度上对盐酸小檗碱的吸收具有促进作用,尤其是在高钙环境下。