光对马卡愈伤组织生长、丛生芽诱导和存活的影响

马卡属于十字花科独行菜属,具有极高的营养价值和药用价值。在快繁过程中,光对马卡愈伤组织生长,丛生芽的诱导和存活有显著的影响。绿光和蓝光既不利于愈伤组织的生长也不利于丛生芽的诱导和存活。白光、红光和黄光能明显促进愈伤组织的生长,在这些光照条件下丛生芽的诱导率为60%～80%,丛生芽存活率为29%～36%。适当延长光照时间可提高丛生芽的存活率,合适的光照时间为16h/d。但是过强的光照可使丛生芽的存活率降低,合适的光照强度为24～41μmol/m2.s。     

光周期对穗花狐尾藻生长、开花与种子形成的影响

通过人工补光和遮光处理,初步研究了光周期对狐尾藻生长和开花的影响。研究发现:8h短日照条件不利于狐尾藻的生长和花序形成,导致狐尾藻不能正常开花和结实;与自然日照长度(平均日照14h)条件下相比,16h长光照条件可以增加植株的高度和分枝数,形成更大的生物量;但24h全光照条件对生长有抑制作用。长光照条件下,狐尾藻花序形成时间和开花时间均比自然条件下延迟,形成花序的数目也显著较自然条件下的少,但长光照条件下形成的种子比自然条件下形成的种子具有更高的萌发率。     

Effects of photoperiod and temperature on diapause induction in Conogethes punctiferalis （Lepidoptera： Pyralidae）

The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day treatments caused larval diapause at 25℃, and the critical photoperiod was between 12 and 13 h （or 12 h 51 min） light per day. No sensitive instar was identified for diapause induction under alternated short- （L ： D 11 ： 13 h） and long-day （L ： D 14 ： 10 h） treatments at different larval stages. However, accumulative treatment of three instars and 10 d under short-day treatment was required for the induction of 50% larval diapause. All larvae entered diapause at 20℃, whereas less than 3% did so at 30℃, irrespective of the long- or short-day treatment. Furthermore, under the short-day treatment, more than 90% of larvae went into diapause with temperatures ≤ 25℃, but less than 17% did so at 28℃. In contrast, under the long-day treatment, less than 19% of larvae went into diapause with temperatures ≥23 ℃. The forward shift （5℃） of critical temperature under the long-day regime demonstrated the compensatory effect of temperature and photoperiod on diapause induction. In conclusion, C. punctiferalis had a temperature-dependent type Ⅰ photoperiodic diapause response; there was no sensitive instar for diapause determination, but the photoperiodic accumulation time countermeasures both of the short-day cycles and the number ofinstars exposed, and the photoperiodic diapause response, was a temperature-compensated phenomenon.     

拟南芥株型突变体zpr1的性状特征与基因鉴定分析

对本研究室经T-DNA插入法获得的拟南芥株型突变株系——隐性突变体zpr1植株进行植物学性状调查和遗传分析,并对该突变基因进行鉴定、表达定位和调控元件分析。结果显示:(1)性状分析表明,与野生型拟南芥Ws-2相比,突变体zpr1的茎生叶分枝数量增加,茎生叶分枝发生于拟南芥顶端花序部位;野生型拟南芥茎生叶为披针形,而突变体zpr1没有出现分枝的茎生叶呈倒卵形,出现分枝的茎生叶呈披针型;突变体zpr1的主花序高度、株高、分枝高度和分枝长度都高于野生型,且分枝数多于野生型。(2)利用质粒挽救和反向PCR法(IPCR)确定了ZPR1基因突变发生位置是该基因起始密码子上游426bp处,证明T-DNA插入破坏了ZPR1基因的启动子区域,导致该基因在拟南芥内不能正常表达。(3)基因转录调控区域的顺式作用元件分析发现在ZPR1基因的转录调控区有多个与植物激素相关的调控元件,还有与光周期调节相关的调控元件。(4)亚细胞定位发现,ZPR1基因在所有细胞中的细胞膜中表达,而在部分细胞的细胞膜、细胞质和细胞核中均有表达。研究表明,ZPR1基因的表达对植物株型发育有重要的调控作用,该基因的表达水平受植物激素和光照的调节,最终导致了植物株型的变化。     

稻飞虱翅型纯系后代个体的翅型分化对光周期变化不敏感

【目的】为了明确光周期和遗传因子在稻飞虱翅型分化中的作用, 研究了3种稻飞虱（褐飞虱Nilaparvata lugens、白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus）翅型纯系或近纯系在不同光照时数下的翅型分化比率。【方法】以经过5~45代连续翅型筛选后的褐飞虱、白背飞虱和灰飞虱的长翅型和短翅型纯系或近纯系为材料, 在室内分别测定了其在长光照（16和20 h）、短光照(4~12 h)和正常光照(14 h) 3类光周期条件下饲养后, 雌、雄成虫中长翅和短翅个体出现的比率及存活率。【结果】白背飞虱和灰飞虱的长翅型纯系M♂×M♀或短翅型纯系B♂×B♀在不同光周期下的翅型比率均无显著差异（P>0.05）。褐飞虱短翅型近纯系B♂×B♀的雌虫短翅率和成虫总短翅率在不同光周期下也无显著差异（P>0.05）, 但雄虫短翅率在正常光照14 h和短光照4 h下显著高于长光照20 h下的（P<0.05）。当褐飞虱短翅型达到纯系后, 其后代翅型在6~16 h光照条件下无显著差异。褐飞虱长翅型近纯系M♂×M♀的后代虽有短翅个体出现, 但是雌虫和雄虫的各自短翅率在不同光周期下无显著差异（P>0.05), 仅总体短翅率在12 h光照条件下的显著高于16 h下的（P<0.05）。褐飞虱长、短翅型杂交筛选品系M♂×B♀的雌虫短翅率随光照时数的延长而升高; 灰飞虱杂交筛选品系M♂×B♀的短翅雄虫随光照时数的缩短而增多（P<0.05）, 但当筛选代次达到45代时, 这种趋势不再显著。3种稻飞虱长翅型和短翅型纯系或近纯系若虫的存活率会稍低于长、短翅型杂交后代的存活率, 但长、短翅型品系的存活率在6~16 h光照条件下差异不显著(P>0.05)。【结论】稻飞虱翅型分化对光周期的反应受飞虱本身遗传背景的影响, 翅型纯系后代个体的翅型分化对光周期变化不敏感。     

Effect of pine foliage damage on the incidence of larval diapause in the pine caterpillar Dendrolimus punctatus （Lepidoptera： Lasiocampidae）

The pine caterpillar Dendrolimus punctatus （Walker） with a larval facultative diapause is one of the most destructive insect pests of the pine tree Pinus massoniana in China. The larvae feeding on pine trees with different damage levels were studied to determine the induction of diapause under both laboratory and field conditions. Developmental duration of larvae before the third instar was the longest when fed with 75%-90% damaged needles, followed by 25%-40% damaged needles and intact pine needles, whereas mortalities did not differ among different treatments under the conditions of 25℃ and critical photoperiod 13.5：10.5 L：D. At 25 ℃, no diapause was induced under 15：9 L：D, whereas 100% diapause occurred under 12：12 L：D regardless of the levels of needle damage. Incidences of larvae entering diapause when they were fed with intact, 25%-40% and 75%- 90% damaged pine needles were 51.7%, 70.8% and 81% under 13.5：10.5 L：D, respectively. Similar results were obtained in the field experiment. Incidence of diapause was significantly different among the pine needle damage levels of pine trees when the photoperiod was close to the critical day length, indicating that the effect of host plants on diapause induction was dependent on the range of photoperiod. The content of amino acid and sugar decreased and tannin increased in pine needles after feeding by the pine caterpillars, suggesting that changed levels of nutrients in damaged needles or a particular substance emitted by damaged pine trees was perhaps involved in the diapause induction of the pine caterpillar.     

光照强度和光周期对醉马草内生真菌共生体幼苗生长和生物碱积累的影响

该研究通过测定不同光周期(8、12、14和16h·d~(-1))和光照强度(1 500、2 500和3 500lux)处理下醉马草内生真菌共生体幼苗的形态指标以及叶绿素、可溶性糖、麦角酰胺和麦角新碱的含量,以明确醉马草内生真菌共生体幼苗生长和生物碱积累的最适光照条件,为醉马草内生真菌共生体的应用提供理论依据。结果发现:(1)醉马草内生真菌共生体幼苗株高、叶绿素和可溶性糖含量随着光照时间的延长而增加,并在光周期为16h·d~(-1)时显著(P0.05)高于其他处理;根长、单株分蘖数和单株生物量均先升高后降低,且均在14h·d~(-1)处理下达到最大值。(2)随着光照强度的增加,醉马草内生真菌共生体幼苗4个形态指标以及叶绿素和可溶性糖含量均呈增加的趋势,并在光照强度为3 500lux时均达到最大值。(3)随着处理时间的延长,醉马草内生真菌共生体幼苗麦角酰胺和麦角新碱的含量在不同光周期处理下均呈上升的趋势,并在光周期为12h·d~(-1)和光照强度为2 500lux处理下麦角酰胺和麦角新碱的含量均显著高于其他处理(P0.05),且在处理第15天时达到最大值。研究表明,适宜的光照环境能显著促进醉马草内生真菌共生体幼苗生长和生物碱的积累,并以12h·d~(-1)光周期和2 500lux光照处理下最有利于麦角酰胺和的麦角新碱积累。     

光照对蔺草生长和草茎开花率的影响

蔺草草茎长度和是否开过花是决定其品质的两个重要方面。试验表明,不同光周期及光照强度对蔺草的生长和草茎开花率会产生显著影响。生育前期,延长日照显著促进开花,遮光处理降低蔺草的分蘖、草茎长度、减少草茎开花率和每花序小花数。中后期对蔺草进行一定遮光处理后,草茎长度增加,开花率下降。试验表明,光照是造成蔺草开花逆转和影响草茎品质的重要生态因子之一。     

山楂叶螨滞育的初步研究

本文采用海绵水盘法研究了山楂叶螨Tetranychus viennensis Zacher的滞育与温度、光照和寄主营养等环境因子的关系。结果表明21℃下,临界光周期为12 h 32 min,光敏感螨态为幼螨至第二若螨之间的连续两个螨态,单独一个发育阶段对短光照不敏感或仅有微弱的感应。在相同寄主（梨树）叶片上,病叶和老叶诱导的滞育率比嫩叶高,分别为69.7%、55.3%和20%。相同叶片,短光照(12.5 h/d)条件下随螨密度的增大滞育率升高。相同短光照下,低温促进滞育,在15℃、18℃和21℃下滞育率分别为100%、93.1%和66.7%;高温（24℃）抑制滞育,滞育率仅为13.3%;温度为27℃时不滞育。     

培养因子对朱蕉试管苗繁殖的影响(简报)

以红边朱蕉试管苗为材料,研究不同光强(1000、2000、3000、5000lx)、不同温度(21、26、31°C)、不同光周期(光照9、14、19、24h/d)对朱蕉芽增殖及生根的影响。结果表明:3000lx,26°C,光照14h/d有利于芽的增殖:而适当增加光强、提高温度、延长光照时间,能促进根的生长。