仙人掌的微繁殖

成功建立了仙人掌离体快繁的实验体系 ,并且对影响微繁殖的一些因素 ,诸如激素组合、外植体的物理状态、大量元素的含量等进行了研究。结果表明 :BA对仙人掌芽增殖具明显作用 ,MS +BA 5 .0mg/L +IBA 0 .1mg/L为最适增殖培养基 ;接种方式实验表明劈接优于整棵。钙、镁离子浓度对试管苗生长没有影响 ,但影响生根数及根长 ;NAA抑制根的伸长 ,但一定浓度可促进生根。总体而言 ,最适的生根培养基为 1 /2MS。同时发现块接比单芽接具有优势。试管苗在形态上出现一些变异。实验结果对仙人掌科其它植物的快速繁殖具有参考意义     

仙人掌超微粉挥发性成分研究

目的：研究仙人掌中的挥发性成分。方法：利用水蒸气蒸馏法提取经超微粉碎后的仙人掌[Opuntia dillenii（Ker-Gaw.）Haw]挥发油,用GC-MS进行测定,结合计算机检索技术对分离的化合物进行结构鉴定,应用色谱峰面积归一化法计算各成分的相对百分含量。结果：共分离鉴定出32个化学成分,占总成分的98.097%,其中相对百分含量大于2%的分别确定为异丁基邻苯二甲酸酯（Isobutyl phthalate）27.492%,棕榈酸（Palmitic acid）16.716%,丁基邻苯二甲酸酯（Butyl phthalate）11.257%,薄荷脑（Menthol）6.722%,亚油酸（Linoleic acid）5.995%,壬醛（Nonanal）4.594%,乙醛（Hexanal）3.614%,十二酸（Dodecanic acid）3.244%。结论：通过对仙人掌超微粉挥发性成分的分析鉴定及相对含量测定,为综合利用仙人掌植物资源等提供科学依据。     

梨果仙人掌红花品系的毒性研究

通过对梨果仙人掌红花品系的小鼠急性毒性试验、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验研究,梨果仙人掌红花品系雌、雄小鼠LD50均大于170．0g／kgBw,属无毒物质;小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验结果均为阴性。因此在本次实验条件下,梨果仙人掌红花品系为无毒物质,未显示有遗传毒性作用。     

Isolation and characterization of polymorphic microsatellite markers in Galapagos prickly pear (Opuntia) cactus species

The Opuntia (prickly pear) genus contains over 200 species. Six of them are endemic to the Galapagos archipelago. Although these cacti are ‘keystone’ species of the Galapagos’ semi‐arid ecosystem, they have never been studied in detail. Because of their current threatened status and their important role in the ecosystem, we developed 16 microsatellite markers to study the population genetic structure of some of these species. These markers display a high level of polymorphism with numbers of alleles per locus ranging from six to 53. Results also revealed possible polyploidy in these cacti.     

Modelling nonlinear dynamics of Crassulacean acid metabolism productivity and water use for global predictions

Crassulacean acid metabolism (CAM) crops are important agricultural commodities in water‐limited environments across the globe, yet modelling of CAM productivity lacks the sophistication of widely used C3 and C4 crop models, in part due to the complex responses of the CAM cycle to environmental conditions. This work builds on recent advances in CAM modelling to provide a framework for estimating CAM biomass yield and water use efficiency from basic principles. These advances, which integrate the CAM circadian rhythm with established models of carbon fixation, stomatal conductance and the soil–plant‐atmosphere continuum, are coupled to models of light attenuation, plant respiration and biomass partitioning. Resulting biomass yield and transpiration for Opuntia ficus‐indica and Agave tequilana are validated against field data and compared with predictions of CAM productivity obtained using the empirically based environmental productivity index. By representing regulation of the circadian state as a nonlinear oscillator, the modelling approach captures the diurnal dynamics of CAM stomatal conductance, allowing the prediction of CAM transpiration and water use efficiency for the first time at the plot scale. This approach may improve estimates of CAM productivity under light‐limiting conditions when compared with previous methods.     

Morphological and phytochemical aspects of three alien Opuntia species on Euganean Hills in North-Eastern Italy

In this study, Opuntia stricta, O. engelmannii, and O. humifusa, naturalized alien units in the Euganean Hills (North-Eastern Italy), are investigated. Different morphological and physiological features both in cladodes collected in summer and winter and in fruits arisen from two blooms are reported. The morphological observations showed a different organization in epidermis/hypodermis of cladodes collected in winter and in summer, probably correlated to the individual plant reaction to a stressful factor as low temperature. Scanning electron microscopy observations revealed no differences in the deposition of waxes and stomata distribution in the epidermis of cladodes. The betacyanin analysis showed that cladodes produce these pigments only in the winter season. In all the species, the higher content of betacyanins was reached in the fruits from the second bloom, with O. stricta being the most rich. The amount of betacyanins is comparable to some commercial red beets used as a common source of betacyanins as natural food color.     

Influences of soil volume and an elevated CO2 level on growth and CO2 exchange for the Crassulacean acid metabolism plant Opuntia ficus-indica

Effects of the current (38 Pa) and an elevated (74 Pa) CO₂ partial pressure on root and shoot areas, biomass accumulation and daily net CO₂ exchange were determined for Opuntia ficus-indica (L.) Miller, a highly productive Crassulacean acid metabolism species cultivated worldwide. Plants were grown in environmentally controlled rooms for 18 weeks in pots of three soil volumes (2 600, 6 500 and 26 000 cm³), the smallest of which was intended to restrict root growth. For plants in the medium-sized soil volume, basal cladodes tended to be thicker and areas of main and lateral roots tended to be greater as the CO₂ level was doubled. Daughter cladodes tended to be initiated sooner at the current compared with the elevated CO₂ level but total areas were similar by 10 weeks. At 10 weeks, daily net CO₂ uptake for the three soil volumes averaged 24% higher for plants growing under elevated compared with current CO₂ levels, but at 18 weeks only 3% enhancement in uptake occurred. Dry weight gain was enhanced 24% by elevated CO₂ during the first 10 weeks but only 8% over 18 weeks. Increasing the soil volume 10-fold led to a greater stimulation of daily net CO₂ uptake and biomass production than did doubling the CO₂ level. At 18 weeks, root biomass doubled and shoot biomass nearly doubled as the soil volume was increased 10-fold; the effects of soil volume tended to be greater for elevated CO₂. The amount of cladode nitrogen per unit dry weight decreased as the CO₂ level was raised and increased as soil volume increased, the latter suggesting that the effects of soil volume could be due to nitrogen limitations.     

Endangered Cactus Restoration: Mitigating the Non-Target Effects of a Biological Control Agent (Cactoblastis cactorum) in Florida

The moth Cactoblastis cactorum (Berg), the poster child of weed biological control in Australia, has recently invaded the United States and threatens native cacti. Concern is greatest for the endangered semaphore cactus, Opuntia corallicola, of which only two known populations exist in the wild. We made three separate outplantings of O. corallicola, designed to bolster the number of extant cacti and to test the effectiveness of three different treatments to protect the cacti from Cactoblastis. In one outplanting, we tested the associational susceptibility hypothesis and found that cacti planted more than 20 m away from the common prickly pear cactus, Opuntia stricta, which act as a reservoir of Cactoblastis, were just as frequently attacked and killed by Cactoblastis as cacti planted within 5 m. In addition, Cactoblastis attack was greater in the shade than in the sun. In the second outplanting, we minimized the attack from Cactoblastis by using protective cages planted at least 500 m from O. stricta in areas not inhabited by cacti. Cages attracted the attention of local animals, which destroyed the cages and trampled the cacti inside to death. Crown rot caused high mortality in this outplanting. In the third outplanting, again conducted at least 500 m away from O. stricta, fertilization did not reduce crown rot mortality. We suggest that increasing populations of O. corallicola in Florida, by means of outplantings, will remain a challenge because of death from Cactoblastis when planted in areas where cacti normally grow and because of death from crown rot in areas where they do not. Because Cactoblastis is moving rapidly northward and westward and has already reached Charleston, South Carolina, rare cacti in the rest of the U.S. Southeast may be in danger. Eventually, many cactus species in the U.S. South, Southwest, and Mexico will likely be threatened by this moth.     

仙人掌多糖对蛋白质糖基化终产物和醛糖还原酶的抑制效应

以仙人掌为原料提取多糖产品,通过超滤浓缩和不同浓度乙醇分级沉淀,分别得到55%乙醇沉淀的多糖(OPMC I),进一步乙醇浓度增至80%沉淀的多糖(OPMCⅡ),以及一次性80%乙醇沉淀的多糖(OPMCⅢ)。比较了三种多糖对蛋白质非酶糖基化反应的终端产物(AGEs)和醛糖还原酶(AR)形成的抑制作用。结果表明,在对AGEs形成的抑制过程中,第四周时OPMC II的抑制作用较强,且强于同剂量的氨基胍;在对AR活性的抑制作用中,OPMC II在三种多糖样品中抑制作用最强,但明显低于阳性对照物依帕司他。