苦难的“小白菜”，解脱的慧定尼

清末杨乃武与小白菜的天大冤案，当时震动朝野，沸沸扬扬。此后由于灵岩樵子黄南丁氏所著小说的敷演，以及在此基础上的戏曲剧目的演出，而广为人知。前几年由于以此为题材的电视剧的热播，更使这一奇案几乎家喻户晓，陶慧敏饰演的小白菜成为深受观众喜爱的艺术形象。但人们熟知的往往只是小白菜的前半生，尤其是与案情及其昭雪有关的一段。至于她此后长达半个世纪多的后半生，一般人则知之甚少了。

苦难的“小白菜”,解脱的慧定尼

杨乃武与小白菜,通过小说和戏剧的渲染,已 成了家喻户晓的人物。但真人真事和艺术作品毕竟 有区别。本文记述的,就是一位真实的小白菜。

小白菜浸制透明标本的制作——显示维管束

初中生物学里,谈到了植物的蒸腾作用,水的运输途径是从根部通过茎到达叶.在讲解这一部分时,都是利用教材中的演示实验来说明,即:在水里切取带叶的茎,插在盛有稀释红墨水的玻璃瓶里,放在阳光下照射3～4 h后,红墨水上升,木质部染成红色.但是,我们用肉眼还是不能很清楚地看出维管束在植物体内的分布情况,用显微镜观察切片,也往往只能看到植物的部分维管束.因此,很难满足我们对一株植物从根部到叶的整个维管束系统的分布和了解.如果有一株整体透明的植物标本,就更能增强教学的直观性.我成功地制作了植物输导组织透明整体标本,由于颜色鲜艳而透明,所以能一目了然地看到植物体中输导组织的分布、位置和数量等,教学效果非常好.现把制作方法介绍如下:

小白菜聊天室

新年新气象．小白菜聊天室也发生了很大的变化。淡蓝色的墙上那红红的标志“Netfriedns”让进入聊天室的朋友眼前一亮。还有鲜艳的窗花、精美的装饰．干净的桌椅．这可是小编们在工作之余亲自设计的温馨风格：聊天室里放着新年的喜庆音乐．朋友们高兴地坐在桌旁聊着天。

Research Progress of Heat-tolerance of Brassica campestris ssp. Chinensis

Brassica campestris ssp. chinensis, also known as non-heading Chinese cabbage, is an important vegetable widely distributed in southern China. High temperature is the most common adversity factor in vegetable production, because Brassica campestris ssp. chinensis is a thermophilic vegetable, which can＇t well grow at high temperature. In summer and autumn, high temperature stress would prevent Brassica campestris ssp. chinensis from growing and result in poor quality of its seedlings, seriously influencing yield and quality of the vegetable in later period. In this paper, present situation and latest advances in heat resistance research of Brassica campestris ssp. chinensis in recent years were reviewed at home and abroad. The research tendency in Bassica campestris ssp. chinensis was also described, providing reference for breeding of heat-resistant Brassica campestris ssp. chinensis.

Embryogenesis and Development of Isolated Microspore in Chinese Cabbage

[Objective] The aim was to observe embryogenesis and development of isolated microspores in Chinese cabbage. [Method] Chinese cabbage F 1 hybrids were used as the experimental materials, and optical microspore was employed to observe the embryogenesis and development of isolated microspores. [Result] Cells swelled after heat shock treatment, which was the critical factor of embryoid induction. Three pathways equal division, unequal division and germination of microspores were discovered to lead to the embryogenesis from isolated microspores after swelling. Microspore could grow directly to embryoid through germination path way. Equally divided microspores formed the original embryos after successive multiple equal divisions. Original embryos could develop into cotyledon-shaped embryos via globular, heart-shaped and torpedo-shaped embryos. The large one of the two cells from unequally divided microspores continued to divide and finally formed a polar embryoid. [Conclusion] The study will provide cytological basis for high induction frequency and embryoid of Chinese cabbage.

Effects of Water and Fertilizer Coupling on Growth and Sound Seedling Index of Green Cabbage Seedlings

[Objective] This study was conducted to investigate the effects of water and fertilizer coupling on growth and sound seedling index of green cabbage seedlings. [Method] A seedling-raising orthogonal test was carried out on green cabbage under different irrigation upper limits and different substrate nutrient levels. [Result] Proper irrigation could promote leaf expansion, while excessive irrigation wa- ter inhibited leaf expansion; fertilization inhibited leaf expansion; and water and fertil- izing coupling showed a superimposed effect on leaf expansion. Proper irrigation promoted stem and root growth; fertilization inhibited stem and root growth; and there was a very strong water and fertilizer interaction effect. Under more irrigation water and proper fertilizing amount, root growth was promoted, stem elongation was inhibited, material accumulation of plants was increased, and sound seedling index was improved. [Conclusion] Water and fertilizer coupling effect could be used for regulating growth and development of various organs of green cabbage and improv- ing seedling-raising efficiency and quality.

A Mutant of PlxyCSP1 Protein in Plutella xylostella

[Objective] This study aimed to explore the effects of cysteine （Cys58） on the characteristics of PlxyCSP1 in P. Iostella combined with pesticide compounds. [Method] Cys58 of PlxyCSP1 was mutated into Trp58 by using overlap extension PCR method, and PlxyCSP1-M2 mutant was obtained. Expression vector was con- structed and the protein was detected by western blot. [Result] Expression vector pET32a-PlxyCSP1-M2 was constructed to express the 35kDa weight protein. [Conclusion] PlxyCSP1 mutant protein has been expressed successfully in prokaryotic ex- pression system.

Responses of Different Pakchoi (Brassica chinensis L.) Cultivars to Cu Toxicity

Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a clean soil to Cu. The response of pakchoi to Cu toxicity varied with the cultivars. The biomass in cultivars of Gaogengbai , Siyueman and Suzhouqing were sensitive to soil Cu pollution, but the cultivars of Heixinwu , Huoqingcai and HKcaixin were relatively tolerant. When the 17 cultiva…

Poultry Manure Compost Alleviates the Phytotoxicity of Soil Cadmium: Influence on Growth of Pakchoi (Brassica chinensis L.)

The growth performance of pakchoi （Brassica chinensis L.） in relation to soil cadmium （Cd） fractionations was investigated to evaluate the remediating effect of poultry manure compost on Cd-contaminated soil. A yellow-brown soil （Alfisol） treated with various levels of Cd （0 50 mg Cd kg^-1 soil） was amended with increasing amounts of compost from 0 to 120 g kg^-1. Compost application transformed 47.8%-69.8% of soluble/exchangeable Cd to the organic-bound fraction, and consequently decreased Cd uptake of pakchoi by 56.2%-62.5% as compared with unamended soil. Alleviation of Cd bioavailability by compost was attributed primarily to the increase of soil pH and complexation of Cd by organic matter including dissolved organic matter. In general, the improvement of pakchoi performance was more pronounced in higher Cd-contaminated soil. Addition of large amount of compost also favored the anti-oxidative capability of pakchoi against Cd toxicity. This low cost remediation method seems to be very effective in the restoration of Cd-eontaminated soils.

Effects of a Composite Soil Amendment on the Quality of Pak Choi(Brassica rapa L. Chinensis Group) Growing in Pb-contaminated Soils

In the present study, a pot experiment was carded out to investigate the effects of a composite soil amendment at different levels （0, 600, 900 and 1 200 mg/kg） on the soil organic matter content, pH, Pb uptake and nutritional quality of pak choi （Brassica rapa L. Chinensis Group） grown in the soils contaminated by four levels （800, 1 200, 1 600 and 2 000 mg/kg） of Pb. The results showed that 900 mg/kg soil amendment increased the soil organic matter content by 24.19%- 60.00%, but had no significant influence on soil pH. Comparing with control （without amendment application）, the security and nutritional quality of pak choi were obviously improved by applying the soil amendment. In detail, 900 mg/kg soil amendment improved the content of Vc of pak choi growing in 800, 1 200, 1 600 and 2 000 mg/kg Pb-contaminated soils by 13.27%-69.30%, the content of soluble sugar by 54.17%- 87.50%, the dry matter weight by 28.36%-33.39%, and decreased the content of Pb by 19.11%-35.72% and the content of crude fiber by 20.83%-31.03%, respectively. These data indicated that the composite amendment can be used for the in situ repair of Pb-contaminated soils, and the recommended dosage is 900 mg/kg.

^(15)N Isotope Techniques for Estimating Effects of Urea-N Fertilizer Application Rate on Yields and Nutrient Contents of Pakchoi Cabbage and Asparagus Lettuce and Nitrogen Utilization Efficiency

A pot experiment combined with15N isotope techniques was conducted to evaluate effects of the varying rates of urea-N fertilizer application on yields,quality,and nitrogen use efficiency (NUE) of pakchoi cabbage (Brassica chinensis L.) and asparagus lettuce (Lactuca saiva L.).15N-labbled urea (5.3515N atom %) was added to pots with 6.5 kg soil of 0.14,0.18,0.21,0.25,and 0.29 g N/kg soil,and applied in two splits:60 percent as basal dressing in the mixture and 40 percent as topdressing.The fresh yields of two vegetable species increased with the increasing input of urea-N,but there was a significant quadratic relationship between the dose of urea-N fertilizer application and the fresh yields.When the dosage of urea-N fertilizer reached a certain value,nitrate readily accumulated in the two kinds of plants due to the decrease in NR activity; furthermore,there was a linear negative correlation between nitrate content and NR activity.With the increasing input of urea-N,ascorbic acid and soluble sugar initially increased,declined after a while,and crude fiber rapidly decreased too.Total absorbed N (TAN),N derived from fertilizer (Ndff),and N derived from soil (Ndfs) increased,and the ratio of Ndff and TAN also increased,but the ratio of Ndfs and TAN as well as NUE of urea-N fertilizer decreased with the increasing input of urea-N.These results suggested that the increasing application of labeled N fertilizer led to the increase in unlabeled N (namely,Ndfs) presumably due to "added nitrogen interaction" (ANI),the decease in NUE of urea-N fertilizer may be due to excess fertilization beyond the levels of plant requirements and the ANI,and the decrease in the two vegetable yields with the increasing addition of urea-N possibly because the excess accumulation of nitrate reached a toxic level.

Allelopathic Effect of Adzuki Bean Root Aqueous Extracts on Four Crops

For choosing suitable summer-planting adzuki bean crop, this experiment adopted the method of indoor petri dish bioassay to study the allelopathy effect of adzuki bean, radish, cabbage and wheat under different concentrations of adzuki bean root aqueous extracts. The result showed that the adzuki bean had a strong inhibition towards its germination rate and germination index. With the increasing concentration of the adzuki bean root aqueous extract, the seed germination rate and germination index of the three kinds of receptor crops presented a decreasing trend. From the root length, spire length, the number of lateral roots, plant height, fresh mass and other morphological indexes of seedlings, it was concluded that with the increase of concentration of adzuki bean root aqueous extract, only wheat pre- sented a promotion effect while the other two kinds of receptor crops showed an inhibition effect, which were not significant at low concentrations. With the increase of concentration of adzuki bean root extracts, the SOD and POD activities of radish and wheat also increased, while the two kinds of enzyme activities of cabbage showed a decreasing trend. The MDA contents in seedlings of radish and wheat decreased, while the MDA content in cabbage increased significantly, which showed that wheat could be used as a rotation crop of adzuki bean, and radish also had a great application potential in adzuki bean crop rotation.

Photosynthetic Pigments Affected by Fertilizer Source in Four Brassica Vegetables

Effect of fertilizer source （mineral fertilizer or organic manure） on photosynthetic pigments leaves content of four brassica vegetables （Pak choi, Kohlrabi, Cauliflower and Cabbage） was tested. Among treatments, cauliflower fertilized with chicken manure had the highest content of chlorophyll a and b （10.08 and 9.37 μm·g^-1）, while, pak choi had the lowest values （2.00 and 2.44 μm·g^-1） in non-fertilized plants. These differences in chlorophyll a and b content may have a great impact on photosynthetic rate and activity. Total carotenoids and total xanthophylls （lutein, zeaxanthin, antheraxanthin and violaxanthin） were the highest in cauliflower while the lowest was in pakchoi, β-carotene, on the other hand, was the highest percentage of total carotenoids （65.7%） in pak choi while Kohlrabi had the lowest percent （57.4%）. This high percentage offl-carotene of total carotenoids may compensate for lower content of chlorophylls and assist for efficient light harvesting process. Lutein showed to be the major components of xanthophyll pigments brassica vegetables and ranged from 0.462μm·g^-1 in cabbage to 0.626μm·g^-1 in kohlrabi but not differed significantly which may refer to genetically controlled. However, lutein, antheraxanthin and zeaxanthin content were increased significantly by the application of chicken manure regardless ofbrassica vegetable type. Violaxanthin was only detected in pak choi and not affected by fertilizer source. It can be concluding from the increasing contents of total xanthophylls pigments that may increase photosynthetic efficiency through non-photochemical quenching process.

Cadmium accumulation in different pakchoi cultivars and screening for pollution-safe cultivars

The selection and breeding of pollution-safe cultivars (PSCs) is a practicable and cost-effective approach to minimize the influx of heavy metal to the human food chain.In this study,both pot-culture and field experiments were conducted to identify and screen out cadmium pollution-safe cultivars (Cd-PSCs) from 50 pakchoi (Brassica rapa L.ssp.chinensis) cultivars for food safety.When treated with 1.0 or 2.5 mg/kg Cd,most of the pakchoi cultivars (>70%) showed greater or similar shoot biomass when compared with the control.This result indicates that pakchoi has a considerable tolerance to soil Cd stress.Cd concentrations in the shoot varied significantly (P<0.05) between cultivars:in two Cd treatments (1.0 and 2.5 mg/kg),the average values were 0.074 and 0.175 mg/kg fresh weight (FW),respectively.Cd concentrations in the shoots of 14 pakchoi cultivars were lower than 0.05 mg/kg FW.In pot-culture experiments,both enrichment factors (EFs) and translocation factors (TFs) of six pakchoi cultivars were lower than 1.0.The field studies further confirmed that the Hangzhouyoudonger,Aijiaoheiye 333,and Zaoshenghuajing cultivars are Cd-PSCs,and are therefore suitable for growth in low Cd-contaminated soils (≤1.2 mg/kg) without any risk to food safety.

Mycorrhizal Inoculation Affects Pb and Cd Accumulation and Translocation in Pakchoi(Brassica chinensis L.)

Heavy metal(HM) contamination in soils is an environmental issue worldwide that threatens the quality and safety of crops and human health. A greenhouse experiment was carried out to investigate the growth, mycorrhizal colonization, and Pb and Cd accumulation of pakchoi(Brassica chinensis L. cv. Suzhou) in response to inoculation with three arbuscular mycorrhizal(AM) fungi(AMF), Funneliformis mosseae, Glomus versiforme, and Rhizophagus intraradices, aimed at exploring how AMF inoculation affected safe crop production by altering plant-soil interaction. The symbiotic relationship was well established between pakchoi and three AMF inocula even under Pb or Cd stress, where the colonization rates in the roots ranged from 24.5% to 38.5%. Compared with the non-inoculated plants, the shoot biomass of the inoculated plants increased by 8.7%–22.1% and 9.2%–24.3% in Pb and Cd addition treatments, respectively. Both glomalin-related soil protein(GRSP) and polyphosphate concentrations reduced as Pb or Cd concentration increased. Arbuscular mycorrhizal fungi inoculation significantly enhanced total absorbed Pb and Cd(except for a few samples) and increased the distribution ratio(root/shoot) in pakchoi at each Pb or Cd addition level. However, the three inocula significantly decreased Pb concentration in pakchoi shoots by 20.6%–67.5% in Pb addition treatments, and significantly reduced Cd concentration in the shoots of pakchoi in the Cd addition treatments(14.3%–54.1%), compared to the non-inoculated plants.Concentrations of Pb and Cd in the shoots of inoculated pakchois were all below the allowable limits of Chinese Food Safety Standard.The translocation factor of Pb or Cd increased significantly with increasing Pb or Cd addition levels, while there was no significant difference among the three AMF inocula at each metal addition level. Meanwhile, compared with the non-inoculated plants, AMF inocula significantly increased soil p H, electrical conductivity, and Pb or Cd concentrations in soil organic matter in the soils at the highest Pb or Cd dose after harvest of pakchoi, whereas the proportion of bioavailable Pb or Cd fraction declined in the AMF inoculated soil. Our study provided the first evidence that AM fungi colonized the roots of pakchoi and indicated the potential application of AMF in the safe production of vegetables in Pb or Cd contaminated soils.

Microbial Biomass and PLFA Profile Changes in Rhizosphere of Pakchoi(Brassica chinensis L.) as Affected by External Cadmium Loading

The effects of root activity on microbial response to cadmium(Cd) loading in the rhizosphere are not well understood.A pot experiment in greenhouse was conducted to investigate the effects of low Cd loading and root activity on microbial biomass and community structure in the rhizosphere of pakchoi(Brassica chinensis L.) on silty clay loam and silt loamy soil.Cd was added into soil as Cd(NO_3)_2 to reach concentrations ranging from 0.00 to 7.00 mg kg^(-1).The microbial biomass carbon(MBC) and community structure were affected by Cd concentration,root activity,and soil type.Lower Cd loading rates(<1.00 mg kg^(-1)) stimulated the growth of pakchoi and microorganisms,but higher Cd concentrations inhibited the growth of microorganisms.The content of phospholipid fatty acids(PLFAs) was sensitive to increased Cd levels.MBC was linearly correlated with the total PLFAs.The content of general PLFAs in the fungi was positively correlated with the available Cd in the soil,whereas those in the bacteria and actinomycetes were negatively correlated with the available Cd in the soil.These results indicated that fungi were more resistant to Cd stress than bacteria or actinomycetes,and the latter was the most sensitive to Cd stress.Microbial biomass was more abundant in the rhizosphere than in the bulk soil.Root activity enhanced the growth of microorganisms and stabilized the microbial community structure in the rhizosphere.PLFA analysis was proven to be sensitive in detecting changes in the soil microbial community in response to Cd stress and root activity.

Effect of Antimony on Physiological Responses of Green Chinese Cabbage and Enzyme Activities of Allitic Udic Ferrisols

High concentrations of antimony(Sb) in soils and vegetables can cause potential health risk. However, the effect of Sb on the growth and response of crops are not well known and to date, there is still no Sb limit standard for Allitic Udic Ferrisols in China. In this study, a greenhouse experiment was carried out to investigate the effect of antimony(Sb) on biomass, physiological performances,and macro- and micronutrient element concentrations of green Chinese cabbage(Brassica chinensis L.), as well as enzyme activities,in Allitic Udic Ferrisols from Hunan Province, China. Antimony was supplied at rates of 0(control), 2, 5, 10, 20, and 50 mg kg-1and thus with the background value of 1.0 mg kg-1, the Sb concentrations in the treated soil samples were 1, 3, 6, 11 21, and 51 mg kg-1, respectively. The results showed the leaf biomass and ascorbic acid content of cabbage significantly(P < 0.05) decreased by 30.6% and 48.3%, respectively, and soil urease and dehydrogenase activities also significantly(P < 0.05) decreased by 33.6%and 32.5%, respectively, when soil Sb concentration was 21 mg kg-1as compared with the control. The uptake of essential nutrient elements such as Mg, Cu, and Zn by cabbage was obviously affected, while the leaf soluble sugar content slightly changed when the soil Sb concentration exceeded 21 mg kg-1. Based on cabbage physiological responses and soil enzyme activities, the permissible concentration of 21 mg kg-1for Sb in Allitic Udic Ferrisols should be recommended.