He—Ne激光对多刺裸腹蚤心脏搏动影响的初步研究

用He—Ne激光(30mw,10分钟,室温)辐照多刺裸腹蚤的心脏或脑神经节,发现多刺裸腹蚤的心跳频率发生降低或增高的变化。停止辐照同一样品在自然培养液中培养24小时后,两处理组的心跳频率都大大增加。本文对这些现象进行了探讨。     

He—Ne激光辐照对葡萄生物学效应的研究

本文报导了激光辐照葡萄芽的生物学效应。He—Ne激光辐照促进了发芽、叶色、枝的生长、早熟结果等一些变化,为激光葡萄育种提供了依据和选育的材料。     

He-Ne激光辐照葡萄抗病性研究

1991年 2月 2 5日 ,用He Ne激光处理四个葡萄品种一年生枝条上的休眠芽 ,经过盆栽 ,移植大田 ;1994年开始挂果。从 1995年至 1999年 5月观察结果表明 :经He Ne激光辐照葡萄休眠芽 ,长成的植株 ,不仅有提早结果 ,促进生长发育的作用 ;更为明显的是增强了葡萄抗病性 ,提高产量 ,改进品质。用He Ne激光辐照葡萄 ,有延迟发病效应。对葡萄黑痘病发病期延迟 7- 8天 ;对葡萄叶斑病发病期延迟 5 - 10天 ;对葡萄白粉病发病期延迟 8- 10天。用He Ne激光辐照葡萄 ,有增强抗病效应。对葡萄黑痘病果穗发病率比对减少 9.83% ;果粒发病率减少16 .2 8%。…     

激光、~(60)Co—r射线对草毒生物效应的研究

本实验用CO_2激光功率密度10.44W/cm~2、3.40W/cm~2,一次10秒及再次6、10、14秒处理草莓、茎尖外植体,可使多数处理的无性后代,产量提高或品质改善。He—Ne激光输出功率10.6mW,原光斑照射30、40秒,也有与CO_2激光相似效应。~(60)Co—r射线吸收剂量193Gy,单独处理及与He—Ne激光30秒复合处理,可改善果实品质,He—Ne激光对~(60)Co—r射线的辐射损伤有修复作用。     

曲酸产生菌激光诱变效应的研究

采用经紫外线(UV)、^60Co、亚硝基胍(NTG)复合诱变得到的黄曲霉曲酸产生菌(UCN7—12),进行激光诱变处理。研究证实在经过UV、^60Co、NTG诱变处理后,黄曲霉突变株用He—Ne激光与YAG激光进行诱变处理仍能提高产酸率,其中He—Ne激光辐照处理20min,正变率为12．1％,产量提高约13％。YAG激光辐照处理300sec,正变率16．7％,产量提高18．3％。说明上述两种激光对黄曲霉曲酸产生菌有一定的诱变效应。     

激光辐照鱼类胚胎导致畸变

红激光(He—Ne,632.8nm)辐照金鱼(Carassius aurafus)受精卵和怀胎孔雀鱼(Poecilia reticulata),导致两种鱼胚胎畸变。金鱼胚胎在某一发自阶段的畸变率随辐照剂量的增加而提高;在同一剂量辐照下,不同发育期的胚胎畸变率各异,胚胎发育初期畸变率最高,此后随胚胎发育过程畸变率下降。经He—Ne激光辐照的孔雀亲鱼也能生产畸形仔鱼。在实验中还比较了红激光(632.8nm)和紫激光(N_2337.1nm)辐照金龟卵致变效果。     

低强度He-Ne激光照射人外周血淋巴细胞两组试验结果的分析

本文采用染色体畸变 (chromosomalaberration CA)试验和微核 (micronucleus)试验两种方法对低强度He Ne激光辐照育龄妇女外周血淋巴细胞。激光能量密度分别为 14.31J cm2 (辐照 5′)、2 8.6 2J cm2 (辐照 10′) ,5 7.2 4J cm2(辐照 2 0′) ,114.5 2J cm2 (辐照 40′)。照射血样后 ,染色体畸变试验检测其淋巴细胞染色体畸变率 ,激光照射及空白对照组 ,血样染色体畸变率分别为 4.2 9‰、3.96‰、3.81、3.5 9‰和 4.19‰ ,X2 检验无显著意义 (P >0 .0 5 )。阳性对照丝裂霉素MMC处理的血样淋巴细胞CA率平均为 14.41‰ ,明显高于激光照射和空白对照组 ,X2 检验有显著差异(P <0 .0 1)。微核试验检测结果 ,微核染色体分别为 1.0 2‰ ,1.17‰ ,1.18‰ ,1.31‰和 1.19‰对照 ,经统计分析激光照射各组与对照组微核率均在 2‰以下 (P >0 .0 5 ) ,属正常人体微核范围内。结果显示两组试验监测诱变均具有一致性。证明He Ne激光辐照人体细胞对染色体无致畸效应。且表明He Ne激光在治疗范围内应用安全、有效、不会对不体造成危害。     

应用酯酶同工酶技术分析激光处理小麦的诱变效应

用He—Ne、Ar~+和CO_23种激光分别辐照小麦浙麦3号干种子,以不处理为对照(CK),在三叶期分别提取酯酶,应用等电聚焦聚丙烯酰胺疑胶(SDS—PAGE)电泳分析其酯酶同工酶,电泳模式表明,He—Ne激光、Ar~+激光处理后出现的酶谱同对照一样,主要集中在Ⅲ区,并有4条相同酶带(Rf=0.88、0.78、0.75和0.71),而CO_2激光处理则出现了16条酶带,其中8条分布在Ⅲ区,6条分布在Ⅱ区,2条分布在Ⅰ区。电泳分析表明,不同激光的诱变效应为:CO_2>He—Ne>Ar~+>CK。     

激光—^60Co—γ辐射诱变小麦生物学效应初步研究

研究小麦品种“绵阳21号”和“汉源小麦”及其~(60)Co—γ一代(γ_1)等四个材料,经N_2和He—Ne激光辐照的20种处理(包括对照)的辐射生物学效应。试验结果表明,激光一代(L_1)植株高度,单株分蘖数,单株有效分蘖数,穗长,小穗数,不实小穗数,退化小穗数,小穗密度,主穗粒数,主穗粒重,分蘖穗粒重,单株粒重,抽穗期,叶面积,穗下轴长,倒一节间长,倒一节间粗等17种性状,都表现出不同处理所引起的生物效应差异。同株高,单株分蘖数、单株有效穗数、主穗长度、不实小穗数,主穗粒数、主穗粒重,单株粒重等8个性关变异系数的比较看出:He—Ne激光(照射10分钟)辐照干种子,“汉源小麦—γ_1”比“汉源小麦”产生的变异大,比对照(未照射)的变异更大。同时,发现不同品种所引起的抽穗期、株高、穗长等14种性状的变异分别达显著或极显著,由剂量不同引起抽穗期、主穗粒重和不实小穗数等三种性状的变异显著。     

激光辐照对绵羊精子代谢和体外获能的影响

本文采用He—Ne激光处理绵羊精液,通过测试精于超弱化学发光强度、TST染色,以了解精子代谢的变化,观察精子顶体反应的发生情况,进一步从受精学角度了解激光的辐照效应。     

He-Ne激光处理不同时期蚕豆幼苗对抗氧化系统的影响

采用功率为3.50 mW/mm2的He-Ne激光处理不同时期蚕豆,研究其四叶期叶片中丙二醛(MDA)含量,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性及同工酶谱的变化。结果表明,与对照相比,He-Ne激光处理不同时期蚕豆,MDA含量均显著降低,且各处理间没有显著差异;SOD、POD、CAT酶活性有不同程度提高。SOD、POD同工酶的酶谱在浸种24小时和胚芽露头期经激光处理后改变,在一叶期处理后没有改变;CAT同工酶谱没有变化;在一叶期处理的三种同工酶谱都没有改变。     

Factors affecting aphid acquisition and transmission of soybean mosaic virus

Myzus persicae transmitted soybean mosaic virus (SMV) most efficiently following 30 or 60 s acquisition probes on infected plants. There were no differences in susceptibility to SMV infection of soybean plants 1 to 12 wk old, but symptoms were more severe in plants inoculated when young than when old. Soybeans inoculated between developmental stages R3 and R6 only showed yellowish-brown blotching on one or more leaves. There were no observable differences in the time of appearance or type of symptoms shown by soybean seedlings inoculated either by sap or by aphids; infected plants became acquisition hosts for aphids 5–6 days after inoculation. There was no change in the efficiency with which M. persicae transmitted SMV from source plants up to 18 wk after inoculation. M. persicae transmitted SMV from leaves of field-grown soybeans when plants were inoculated at developmental stages V6, R2, and R3 and tested as sources 57–74 days after inoculation but not from plants inoculated at R5 and tested as sources 14 to 32 days after inoculation. M. persicae acquired SMV from soybean buds, flowers, green bean pods, and unifoliolate, trifoliolate, and senescent leaves. Middle-aged and deformed leaves were better sources of the virus than buds, unfolding and old symptomless leaves. The results are being incorporated into a computer model of SMV epidemiology.     

He-Ne激光处理对拟南芥种子萌发和幼苗生长特性的影响

以哥伦比亚生态型(Columbia-0)的野生型拟南芥为材料,利用He-Ne激光生物辐照仪(632.8nm,5mW/mm2)处理拟南芥种子,统计其发芽势和发芽率,并测定根长及叶绿素、可溶性糖、可溶性蛋白和丙二醛(MDA)的含量,以探讨He-Ne激光对拟南芥种子萌发和幼苗生长的影响。结果显示,短时间的He-Ne激光辐照可促进拟南芥的生长发育,且最佳辐照时间为4min,此时的发芽势、发芽率、根长、叶绿素、可溶性糖及可溶性蛋白的含量均达到最大,而丙二醛(MDA)的含量为最低。当辐照时间大于4min时,促进作用逐渐变小,且随着辐照时间的延长而表现出抑制作用。研究表明,适量的He-Ne激光辐照在一定程度上可以促进拟南芥种子的萌发和幼苗生长以及保护其细胞膜免受伤害。     

Abscisic Acid Sprays Significantly Increase Yield per Plant in Vineyard-Grown Wine Grape (<Emphasis Type="Italic">Vitis vinifera</Emphasis> L.) cv. Cabernet Sauvignon Through Increased Berry Set with No Negative Effects on Anthocyanin Content and Total Polyphenol Index of Both Juice and Wine

In many cultivars of Vitis vinifera periods of mild water stress during ripening are thought to increase grape quality for winemaking, even though yields may be negatively affected. Because abscisic acid (ABA) is involved in the signaling of water stress in plants, we examine the effects of the ABA signal being given without the concomitant water stress. ABA at 250 mg l⁻¹ was sprayed weekly or biweekly from bud-burst until harvest onto the leaves of vineyard-grown plants of cv. Cabernet Sauvignon. For ABA-treated plants berry yield per bunch and per plant was significantly increased (1.5- to 2.0-fold) across three consecutive harvests (2005 through 2007). Number of berries per bunch and per plant was the primary basis for the significant crop increases, although bunches per plant also tended to increase (1.1- to 1.3-fold) across all three harvests. Other parameters assessed included number of internodes, shoot length, leaf area, leaf water potential at midday, photosynthesis, and stomatal conductance. These parameters showed no significant change with ABA treatment, although shoot length tended to be reduced, as was leaf area relative to control plants. The significantly increased fruit yields were thus accomplished without accompanying increases in leaf photosynthesis and leaf areas. Juice at harvest had equal levels of sugars (Brix) and somewhat higher levels of anthocyanins and total polyphenols relative to control values. The two latter trends continued for the resultant wine across two vintage years. In conclusion, three seasons of experimental trials have demonstrated that ABA application can significantly enhance yield per plant in the field-grown grape (cv. Cabernet Sauvignon) by favoring increased berry set without diminishing the quality of the fruit for winemaking use.     

Responses of He-Ne laser on agronomic traits and the crosstalk between UVR8 signaling and phytochrome B signaling pathway in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> subjected to supplementary ultraviolet-B (UV-B) stress

UV-B acclimation effects and UV-B damage repair induced by a 632.8-nm He-Ne laser were investigated in Arabidopsis thaliana plants in response to supplementary UV-B stress. There was an increasing trend in growth parameters in the combination-treated plants with He-Ne laser and UV-B light compared to those stressed with enhanced UV-B light alone during different developmental stages of plants. The photosynthetic efficiency (Pn) and survival rates of seedlings were significantly higher in the combination treatments than UV-B stress alone. The expression of UVR8, phytochrome B (PhyB), and their mediated signal responsive genes such as COP1, HY5, and CHS were also significantly upregulated in plants with the laser irradiation compared with other groups without the laser. Levels of flavonol accumulation in leaves and capsule yield of He-Ne laser-treated plants were increased. The phyB-9 mutants were more sensitive to enhanced UV-B stress and had no obvious improvements in plant phenotypic development and physiological damage caused by enhanced UV-B stress after He-Ne laser irradiation. Our results suggested that UVR8 and its mediated signaling pathway via interaction with COP1 can be induced by He-Ne laser, and these processes were dependent on cytoplasmic PhyB levels in plant cells, which might be one of the most important mechanisms of He-Ne laser on UV-B protection and UV-B damage repair. These current data have also elucidated that the biostimulatory effects of He-Ne laser on Arabidopsis thaliana plants would happen not only during the early growth stage but also during the entire late developmental stage.     

Increased susceptibility of black-currant bushes to the gall-mite vector (Phytoptusribis Nal.) following infection with reversion virus

Healthy black-currant bushes (var. Wellington XXX) and others infected systemically with a virulent strain of reversion virus were exposed equally to infestation by the gall-mite vector (Phytoptus ribis Nal.). Shoots with malformed leaves caused by mites feeding at the stem apices were virtually restricted to the virus-infected bushes. Buds infested with mites became rounded galls, which were far fewer and more localized on shoots of healthy bushes than on infected ones. Similar results were obtained in further experiments with Wellington XXX and seven other varieties. Bushes infected systemically with an avirulent strain of reversion virus developed more galls than healthy bushes, but fewer galls than bushes infected with a virulent strain. The young buds of virus-infected bushes were 170 times more susceptible to dispersing mites than those of healthy bushes. The axillary buds of healthy bushes resisted infestation and the apical meristems were virtually inaccessible to mites, whereas the axillary and apical buds of virus-infected bushes were invaded readily. An experiment with bushes var. Cotswold Cross that were either healthy or partially or completely infected with reversion virus was retained for two years. Each year there was a relationship between symptom expression and mite infestation; only shoots with chronic virus symptoms developed mite-affected leaves and numerous galls. Virus infection increased the vulnerability and accessibility of the apical and axillary buds by decreasing the density of hairs on the stems and leaves. Infected bushes also presented a greater catchment area to dispersing mites and more shoots and buds were available for colonization than on healthy bushes. The interactions between virus, host and vector are discussed, together with their implications in nature, in experimental design and in disease control.     

Branch development in Lupinus angustifolius L.#I. Not all branches have the same potential growth rate

Although the basal and uppermost lateral branches of Lupinus angustifolius L. frequently grow and contribute to yield, buds formed in the axils of leaves 6-12 (referred to as middle buds) rarely grow. This may be due to an inherent limitation of these buds, or some form of apical dominance or competition imposed by the plant. The hypothesis that middle buds have the full capacity to grow, but remain suppressed on intact plants was tested. The main stem apex and buds from the axils of leaves 1 and 8 (bud 1 and bud 8) were excised and cultured on sterile agar. The buds were removed from culture and weighed every 2-3 d for 21 d. The growth rate of apices from the main stem was approximately 5.8 mg d^-1, compared to 2.4 mg d^-1 for bud 1 and 0.9 mg d^-1 for bud 8. Buds in the axils of leaves 6-10 on intact plants were painted six times with a synthetic cytokinin, benzylaminopurine, from 40 d after sowing. This promoted rapid elongation and thickening of these buds, visible as early as 5 d after painting began. The rapid growth of these branches was associated with a reduction in the length of the remaining branches on the plant. However, excision of lower branches did not increase the growth of the middle buds. It is concluded that buds 6-12 of Lupinus angustifolius L. have a partial potential to grow. This potential appears to be limited by innate factors in the bud, and may be structural and/or hormonal. The limitation appears to develop very early in the plant, and potential growth is not modified by subsequent nutrition of the plant.     

Host plant suitability and feeding preferences of the grapevine pest Abagrotis orbis (Lepidoptera: Noctuidae)

Thirteen plant species were tested for their suitability as hosts for Abagrotis orbis (Grote), a climbing cutworm pest of grapevines in British Columbia. Choice tests were also conducted to investigate larval feeding preferences for the Brassicaceae species joi choi, Brassica rapa variety. Chinensis L., spring draba; Draba verna L.; and shepherd's purse, Capsella bursa-pastoris (L.) Medik; compared with postdormant buds of grape, Vitis vinifera L. (Vitaceae), and leaves of nine other plant species from several families. Results showed that tah tsai, Brassica rapa L. variety rosularis (M. Tsen & S. H. Lee) Hanelt (Brassicaceae), is a superior host for A. orbis based on shorter time to adult eclosion, heavier pupae, and higher rates of survival. Later-instar larvae died when fed draba, whereas those reared on shepherd's purse did not survive beyond the third instar. White clover, Trifolium repens L. (Fabaceae), and grape leaves were unsuitable hosts throughout development. Fifth-instar A. orbis preferred plants of the Brassicaceae family, dandelion, Taraxacum officinale Weber (Asteraceae), and strawberry, Fragaria sp. L. (Rosaceae), compared with postdormant grape buds. The results of this study suggest that the winter annual mustards draba and shepherd's purse that often grow abundantly in vine rows might help reduce climbing cutworm damage to the buds of grapevines.     

Diagnosis of light leaf spot (Pyrenopeziza brassicae) on winter oilseed rape (Brassica napus) in the UK

Light leaf spot lesions were generally first observed as light green areas on leaves of UK winter oilseed rape crops in January or February and later became brittle and bleached. Elongated lesions, which were brown with indistinct edges, developed on stems in the spring and summer, when lesions were also observed on flower buds, pedicels and pods. Development of diagnostic white pustules (spore masses of Pyrenopeziza brassicae, which erupt through surfaces of infected tissues) for confirmation of light leaf spot infection on symptomless plants or plants with indistinct or ambiguous symptoms in the autumn, winter or spring was enhanced by incubating plants in polyethylene bags. In experiments with artificially inoculated plants, glasshouse-grown plants exposed in infected crops and plants sampled from crops, white pustules developed at all incubation temperatures from 2^oC to 20^oC on infected leaves of different cultivars. The period of incubation required before the appearance of pustules decreased as the time that had already elapsed since the initial infection increased. The longest periods of incubation were required at the lowest temperatures (2^oC or 5^oC) but leaves senesced and abscised from plants most quickly at the highest temperatures (15^oC or 20^oC), suggesting that the optimal incubation temperature was between 10^oC and 15^oC.