稻水象甲Lissorhoptrus oryzophilus Kuschel卵巢、飞行肌及消长动态研究

本文在福鼎对稻水象甲消长动态进行了调查．并对成虫卵巢、飞行肌进行了解剖。通过解剖,所预测的各虫态发生期厦一代成虫迁移期与田间调查结果基本吻合。稻水象甲产卵高峰在4月底至5月上旬．幼虫、蛹和一代成虫的盛发期分别在5月上中旬、6月中下旬和6月下旬;一代成虫在6月下旬开始从稻田迁出。飞行肌解剖结果表明,飞行肌宽度随时间变化而变化,而长度则比较恒定,与发育历期无关,所以飞行肌宽度可作为监测依据,而长度则不宜采用。     

基于ISSR分子标记技术的稻水象甲遗传多样性研究

稻水象甲Lissorhoptrus oryzophilus Kuschel是一种世界性的水稻害虫,已侵入我国23个省市区,发生面积近千万亩。为弄清我国不同地区稻水象甲的遗传多样性水平、居群间的遗传分化及可能的扩散路线,本研究采用ISSR分子标记技术分析了我国13个省28个地区稻水象甲样本的遗传多样性。利用15条ISSR引物共扩增得到258条带,其中247条为多态性条带。在物种水平上,稻水象甲的多态位点百分率(PPB)为95.73%,Nei's基因多样性(H)为0.3578,Shannon信息多样性指数(I)为0.5330;在居群水平上,以上3项指标的平均值分别为46.28%、0.1768、0.2620。Nei's基因分化系数Gst为0.5059,表明有50.59%的遗传变异存在于居群间,49.41%的遗传变异存在于居群内,居群间表现出较高水平的遗传分化。通过UPGMA聚类可将稻水象甲28个居群分成2大支系:安徽池州、安徽合肥、云南嵩明、云南曲靖、江西南昌、四川盐亭、辽宁盘锦、辽宁东港、山西太原、山东东营、天津蓟县、陕西城固、河北唐山、云南寻甸等14个居群聚成第一个分支;贵州、贵州开阳、贵州龙里、贵州贵阳、贵州修文、四川隆昌、四川泸州、湖北武当山、湖北荆门、湖北利川、湖南宁乡、湖南双峰、湖南邵阳、天津宝坻等聚成第二个分支。     

稻水象甲田间种群动态及化学控制技术

稻水象甲在福建省霞浦县长春镇田间种群发生动态的调查结果表明:5月中旬是稻水象甲越冬代成虫迁入稻田为害高峰期,5月下旬成虫种群数量迅速降低,并有少量幼虫开始为害水稻根部;6月初是幼虫发生为害高峰期,蛹高峰期出现在6月中旬,并开始有一代成虫羽化。药剂筛选试验结果表明:20%丁硫克百威乳油、48%毒死蜱乳油、40%三唑磷乳油、5%锐劲特悬浮剂对稻水象甲成虫具有良好的田间控制效果,药后7d防效均在92.31%—100%;5%丁硫克百威颗粒剂、15%乐斯本颗粒剂、3%呋喃丹颗粒剂施药后7d对稻水象甲幼虫的防效90.03%—93.56%。化学综合防治示范区水稻分蘖数和株高均显著大于对照区。     

稻水象甲越冬成虫的耐寒力测定

测定了浙江乐清 (北纬 2 8 1 4°,东经 1 2 0 94°)稻水象甲LissorhoptrusoryzophilusKuschel越冬成虫的耐寒力 ,从 1 1月下旬至 3月下旬平均过冷却点温度为 -1 5 3～ -2 1 2℃ ,结冰点温度为 -1 4 0～ -1 8 6℃。结合发生地气温条件 ,讨论了该地冬春季低温对该虫越冬群存活的影响。     

The influence of rice plant age on susceptibility to the rice water weevil,Lissorhoptrus oryzophilus

Plant age‐ and plant stage‐related changes in the resistance of rice, Oryza sativa, to its most important insect pest in the US, the rice water weevil (Lissorhoptrus oryzophilus), were investigated in a series of field and greenhouse choice and no‐choice studies. Rice plants were susceptible to infestation by rice water weevils over a broad range of plant ontogenetic stages, from at least the early vegetative stage to well into the reproductive stage. There was, however, a clear preference expressed by rice water weevils in both choice and no‐choice experiments for plants in (or nearly in) the tillering stage of development, with pre‐tillering and reproductive stage plants less preferred. The relationship between rice plant age and susceptibility to weevils is thus nonlinear. This study constitutes one of the most thorough studies to date of the relationship in a grass species between plant age and susceptibility to herbivores. The results provide a biological explanation for observed patterns of weevil infestations and a rationale for the cultural practice of delayed flooding.     

稻水象甲卵的空间分布型及抽样技术研究

本文利用Taylor幂法则和Iwao回归法对稻水象甲LissorhoptrusoryzophilusKuschel卵的空间分布型进行了测定 ,结果表明稻水象甲卵在田间呈聚集分布 ,且符合负二项分布 ,k值为 0 4 796。其种群聚集主要是由环境因子引起的。应用Iwao的抽样模型建立了稻水象甲卵的田间理论抽样数公式 :N =1D2 1 784 6M + 0 2 4 2 5 。并根据Gerrard的零频率模型建立了估计该种群平均密度的零频率模型 :X =1 5 787( -lnP0 ) 1 0 62 5。     

稻水象甲成虫活动行为的日节律

为了摸清稻水象甲Lissorhoptrus oryzophilus Kuschel成虫在稻田中的日活动行为节律, 采用室外单头隔离饲养的方法, 将成虫 行为分为移动、 取食、 离水静息、 触水静息和其他5个行为类型, 每30 min观察记录1次, 从2012年4月30日至5月4日连续观察5 d, 共获得7 200个行为数据。结果显示： 稻水象甲越冬成虫行为的日时间分配以离水静息行为最多（47.83%）, 移动行为最少（5.64%）, 各行为的时间分配存在极显著差异（P<0.001）。离水静息行为最高峰值在23:30 （72.67%）, 最低值在7:30 （14.67%）; 触水静息行 为最大峰值在7:30 （75.33%）, 19:00还有一个小高峰（37.33%）; 取食行为在15:00达到最高峰（26.67%）, 在21:00达到第2个高峰 值（18.00%）; 移动行为在22:00-9:00较少（0~4.00%）, 从9:30开始持续增加, 在17:00达到最高峰（20.00%）; 其他行为在 1.33~18.67%之间波动。离水静息、 移动、 取食和其他行为白天和黑夜存在极显著差异（P<0.001）, 但触水静息行为白天和黑夜无显著 不同（P=0.834）; 上午、 中午、 下午和晚上4个时间段之间各行为也有显著差异（P<0.001）。在空间上, 离水静息行为在叶片上最高 , 移动行为以水中最高, 取食行为仅发生在叶片上, 离水静息、 移动和取食在水稻不同部位存在极显著差异（P<0.001）。水中发生触 水静息、 移动和其他共3种行为, 以触水静息行为的日波动最大, 3种行为在各时刻之间有极显著差异（触水静息和移动： P<0.001; 其他： P=0.002）; 叶片上发生离水静息、 移动和取食3种行为, 以离水静息和取食行为的日波动较大且在各时刻间具有极显著的差异 （P<0.001）; 茎秆和瓶壁或封口纱布处主要发生离水静息和移动行为, 所占比例均不高, 但在瓶壁或封口纱布处的移动行为各时刻之 间有极显著差异（P=0.008）。水中和叶片上是行为发生的主要空间, 在水中行为的最高峰值（81.33%）与叶片上的最低值（12.00%）出 现时间相同, 为7:30, 一天中各时刻水中和叶片上的行为呈交错性变化。结果提示, 稻水象甲成虫活动行为受到时空变化的影响, 且 时间变化对其行为的影响较空间变化更为明显。     

稻水象甲种群增长规律初探

扣笼接虫观测稻水象甲不同接虫密度所产下代虫量。结果表明,稻水象甲种群增长具有明显密度依赖性,接虫密度X越大,代间增殖倍率Y2越低。X-Y2关系用Y2=1/(0.836 0.421X)的双曲线拟合良好。以水稻移栽后稻田成虫密度N为指标,越冬成虫存活率为S0,防治后成虫残存率为S1,则第t 1年种群密度关系可表述为：Nt 1=S0S1Nt/(0.0836 0.0421S0S1Nt)。模型参数值稳定,拟合度好,模型描述的种群增长规律与稻水象甲侵入辽宁省以来种群增长的实际情况相吻合。用该模型预测辽宁省不同地区稻水象甲的发生趋势其准确率高,并可指导稻水象甲的综合防治。     

Effects of defoliation on the resistance and tolerance of rice,Oryza sativa,to root injury by the rice water weevil,Lissorhoptrus oryzophilus

Understanding plant‐mediated interactions in agricultural systems may facilitate the development of novel and improved management practices, which is important, as management of these insects is currently heavily reliant on insecticides. The fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae, Prodeniini), is a sporadic pest of rice fields in the southern USA. In southwestern Louisiana, this defoliating insect typically attacks rice early in the growth season, before fields are flooded. Defoliation by fall armyworm larvae may trigger increased expression of plant defenses, which may result in increased resistance to subsequent herbivores. The rice water weevil (RWW), Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae, Stenopelmini), enters rice fields as an adult both before and after flooding, but oviposition and larval infestation occur only after fields are flooded. RWW may be affected by changes in plant resistance caused by fall armyworm defoliation before flooding. The objectives of this study were to investigate the plant‐mediated effects of natural and artificial defoliation on population densities of RWW larvae after flooding and on the ability of rice plants to compensate for root injury by RWW larvae. In the 2015 season, fall armyworm defoliation before flooding resulted in reduced RWW densities after flooding. However, in 2016 no significant effects of fall armyworm defoliation on densities of RWW larvae were detected. Similarly, mechanical defoliation of rice before flooding did not affect RWW densities after flooding. Although lowest yields were observed in plots subjected to both root injury and defoliation, there was little evidence of a greater than additive reduction in yields from simultaneous injury. These results suggest a lack of plant‐mediated interactions among these two pests in rice in the southern USA.     

中国北方稻水象甲种群与美国两性生殖型种群触角形态特征的比较研究

为了揭示孤雌生殖型稻水象甲不同种群触角的形态变异,明确两性生殖型与孤雌生殖型稻水象甲触角形态特征差异。分析了来自于吉林通化(TH)、吉林公主岭(GZL)、辽宁沈阳东陵区(DL)、辽宁沈阳苏家屯(SJT)、山东东营(DY)5个孤雌生殖稻水象甲触角各节的长度和最大宽度,并与美国两性生殖型稻水象甲成虫触角进行了比较。结果表明孤雌生殖型雌性的触角柄节长度、触角总长度明显长于两性生殖型雌性的(P0.01)。除柄节外,孤雌生殖型雌性触角各节的宽度均明显宽于两性生殖型雌性(P0.01)。两种生殖型稻水象甲雌性触角梗节以及第3、4、6鞭小节的最大宽度范围不重叠。吉林通化种群(TH)与其他4个中国北方种群之间触角有显著性差异。两性生殖型稻水象甲雄性的触角总长度和柄节长度均明显长于雌性(P0.01),且雄性柄节长度范围(310.45-316.22μm)与雌性的范围(282.12-294.56μm)不重叠。结果提示,柄节长度可以鉴别本研究中两性生殖型稻水象甲雌雄个体;触角梗节以及第3、4、6鞭小节的最大宽度范围可以鉴别本研究中2种生殖型雌性个体。     

稻水象甲(Lissorhoptrus oryzophilus Kuschel)滞育征候群中的飞行行为

１９９４－１９９６年对浙江省双季稻区稻水象甲（ＬｉｓｓｏｒｈｏｐｔｒｕｓｏｒｙｚｏｐｈｉｌｕｓＫｕｓｃｈｅｌ）飞行行为的研究表明,稻水象甲飞行扩散的行为特征是：（１）长时间的起飞准备和不高的起飞成功率,每晚的迁出率只有三分之一左右,（２）卵巢,飞行肌呈季节性消长而无局地飞行（ｔｒｉｖｉａｌｆｌｉｇｈｔ）;（３）飞行速度不高,飞行能力不强,且风力稍大便无法起飞,一般情况下不会形成远距离自然扩散,因此     

稻水象甲(Lissorhoptrus oryzophilus Kuschel)滞育征候群中的飞行行为

１９９４～１９９６ 年对浙江省双季稻区稻水象甲（ Ｌｉｓｓｏｒｈｏｐｔｒｕｓ ｏｒｙｚｏｐｈｉｌｕｓ Ｋｕｓｃｈｅｌ）飞行行为的研究表明,稻水象甲飞行扩散的行为特征是：①长时间的起飞准备和不高的起飞成功率,每晚的迁出率只有三分之一左右;②卵巢、飞行肌呈季节性消长而无局地飞行（ｔｒｉｖｉａｌｆｌｉｇｈｔ）;③飞行速度不高,飞行能力不强,且风力稍大便无法起飞,一般情况下不会形成远距离自然扩散。因此,严格控制人为传带是控制疫区扩大的有效途径。     

播栽期对水稻产量和产量构成因素及生育期的影响

研究了不同播栽期对水稻产量和产量构成因素及生育期的影响。结果表明 ,随播栽期推迟 ,水稻产量有所降低。每穗成粒数减少是推迟播栽期引起水稻减产的主要原因 ,其次是千粒重的下降和成穗数的降低。针对目前的生产实际 ,提出了一些应对播栽期推迟的技术措施。     

稻鸭共育复合系统对水稻生长与产量的影响

通过田间对比试验,研究了稻田全天候家鸭野养对水稻生长发育及其稻谷产量的影响.结果表明,在稻鸭共育复合生态系统中,由于鸭在稻间的活动明显改善了水稻群体质量,水稻无效分蘖比不养鸭对照显著减少,提高成穗率8.08%,增加水稻群体基部透光率4.05%;齐穗期和成熟期的绿叶面积比不养鸭对照分别增加6.01%和10.65%,叶片叶绿素含量增加2.90%和17.82%;齐穗期的根系活力和灌浆期剑叶的光合作用强度分别比不养鸭对照增加24.02%和15.73%,从而积累较多的有机同化物,提高经济系数2.87%,增产稻谷4.93%,最终实现了水稻良好生育和高产、高效的目标.     

OsPIN5b modulates rice (Oryza sativa) plant architecture and yield by changing auxin homeostasis,transport and distribution

Plant architecture attributes such as tillering, plant height and panicle size are important agronomic traits that determine rice (Oryza sativa) productivity. Here, we report that altered auxin content, transport and distribution affect these traits, and hence rice yield. Overexpression of the auxin efflux carrier‐like gene OsPIN5b causes pleiotropic effects, mainly reducing plant height, leaf and tiller number, shoot and root biomass, seed‐setting rate, panicle length and yield parameters. Conversely, reduced expression of OsPIN5b results in higher tiller number, more vigorous root system, longer panicles and increased yield. We show that OsPIN5b is an endoplasmic reticulum (ER) ‐localized protein that participates in auxin homeostasis, transport and distribution in vivo. This work describes an example of an auxin‐related gene where modulating its expression can simultaneously improve plant architecture and yield potential in rice, and reveals an important effect of hormonal signaling on these traits.     

The influence of plant age on tolerance of rice to injury by the rice water weevil,Lissorhoptrus oryzophilus (Coleoptera: Curculionidae)

For most plant species, tolerance to many types of herbivory increases as plants age, but the applicability of this pattern to root herbivory has not been tested. Injury to roots of rice plants by larvae of the rice water weevil, Lissorhoptrus oryzophilus Kuschel, causes severe reductions in yields in the United States. It is generally thought that young rice plants, because their root systems are smaller, are less tolerant than older plants of root feeding by L. oryzophilus. Field experiments were conducted to test this hypothesis. Plots of rice (4.7 to 6.5 m2) were established and subjected to natural infestations of L. oryzophilus larvae. A soil insecticide was applied to plots at different times during the tillering phase of rice in order to manipulate the timing of weevil infestation. The impact of these treatments (timings of insecticide applications) was assessed by comparing relationships between yield loss and larval pressure for each treatment using analysis of covariance. Yield losses ranged from 13% to over 40% in plots not treated with insecticide. Patterns of yield losses from plots treated with insecticide at different times were best explained by the hypothesis that yield loss is determined both by the age of plants infested and by the size of larvae infesting plants. Young plants appear to be less tolerant than older plants, and feeding by large larvae appears to be more deleterious than feeding by smaller larvae. Management practices that delay infestation of rice by L. oryzophilus until plants are older may be an important component of management programmes for this pest.     

不同水分和氮素处理对寒地水稻生育及产量的影响

为了探讨不同水分和氮素处理对寒地水稻生长发育及产量的影响,以水稻品种空育131、龙粳21为试验材料,于2010—2011年度在黑龙江建三江进行水分、氮素处理大田试验,水分为雨养、间歇灌溉、水层灌溉3个水平,氮素为不施氮、常规施氮(112—135 kg/hm2)、高氮(142—173 kg/hm2)3个水平。结果表明:与水层灌溉相比,雨养水稻生育期缩短1—5 d,生长指标明显降低,产量显著降低,间歇灌溉水稻生育期、生长指标与其相似,产量差异不显著。与常规施氮相比,不施氮生育期缩短2—5 d,高氮条件下延长2—4 d;施氮量增加,生长指标增大,产量显著增加;低氮条件下,水分不足的限制作用明显,高氮能一定程度弥补水分的限制,促进水稻生长。增加施氮量及灌溉水平可以显著地提高有效穗数、每穗粒数。在试验条件下,水氮互作效应不显著。间歇灌溉及高氮管理具有较好的增产效应及资源利用率,研究可为寒地水稻生产进行水氮科学管理、实现高产高效提供理论依据。     

Effects of water stress on plant growth and root proteins in three cultivars of rice (Oryza sativa) with different levels of drought tolerance

Rice ( Oryza sativa L.) is considered a drought-sensitive crop species; however, within this species, there are considerable varietal differences in sensitivity to this environmental stress. In the present work, the effect of water stress on germination, plant growth and root proteins in three rice cultivars (Sinaloa, IR10120 and Chiapas) was analyzed. Seed germination and plant growth were found to be significantly inhibited by polyethylene glycol (PEG)-imposed water deficit in cv. Sinaloa; cvs IR10120 and Chiapas were more tolerant to water stress. Fluorographs of two-dimensional electropherograms of in vivo-labeled polypeptides were analyzed to identify changes in the root protein patterns that resulted when plants were grown in the presence of 10% PEG for 10 days. The treatment induced or increased the synthesis of eight polypeptides or groups of polypeptides in cv. Sinaloa, seven in cv, IR10120 and four in cv. Chiapas. The synthesis of several polypeptides was decreased by the PEG treatment in cv. Sinaloa and cv. IR10120. Most of these PEG-induced changes in the root protein patterns were cultivar-specific and only one 26-kDa protein with a pI of 6.0 was induced by water deficit in the two cultivars Sinaloa and IR10120.     

Enhanced UV-B radiation has little effect on growth, δ13C values and pigments of pot-grown rice (Oryza sativa) in the field

Predicted increase in ultraviolet-B (UV-B: 280–320 mn) radiation may have adverse impacts on growth and yield of rice ( Oryza sativa L.), as has been found in studies hitherto. However, most of the studies were conducted in growth chambers or greenhouses where the plants are generally more sensitive to UV-B than in the field, presumably because of the distorted balance between UV-B and ultraviolet-A as well as PAR. This study was conducted to address the effects of enhanced UV-B on growth and yield of rice under a realistic spectral balance in the field. Three cultivars, "Koshihikari",'IR 45'and'IR 74'were pot-grown and irradiated with enhanced UV-B for most of the growing season in the field at Tsukuba, Japan (36°01'N, 140°07'E). The UV-B enhancement simulated ca 38% depletion of stratospheric ozone at Tsukuba. The results showed no UV-B effects on plant height, numbers of tillers and panicles, dry weight of the plant parts or the grain yield for any of the 3 cultivars. Natural abundance of ¹³C in the flag leaves was not altered by the UV-B enhancement either. While UV-absorbing compounds showed no response to the UV-B enhancement, chlorophyll contents decreased with enhanced UV-B. However, the decrease of chlorophyll was limited to an early growth stage with no effect later. We thus found no extraordinary impact of the nearly doubled UV-B radiation on rice in the field, and it would appear that a reliable prediction of the effects of UV-B will require experiments carried out over a number of years under various climatic and solar UV-B regimes.     

Azospirillum amazonense inoculation: effects on growth, yield and N2 fixation of rice (Oryza sativa L.)

Bacteria of the genus Azospirillum are considered to be plant-growth promoting bacteria (PGPR) and stimulate plant growth directly either by synthesising phyto-hormones or by promoting nutrition by the process of biological nitrogen fixation (BNF). Although this genus extensively studied, the effects of inoculation and the possible BNF contribution of the Azospirillum amazonense specie are very scarce. The aim of this study was to isolate, characterise and evaluate auxin production and nitrogenase activity of this species and to select, by inoculation of rice plants, promising isolates based on their ability to improve plant growth, yield and the BNF contribution. One hundred and ten isolates obtained from rice were characterised and grouped according to colony features. Forty-two isolates, confirmed as A. amazonense by the fluorescent in situ hybridization (FISH) technique, were tested for auxin production and nitrogenase activity in vitro. Subsequently plant growth promotion related to plant nutrition effect was evaluated, in vitro and in greenhouse experiments. The BNF contribution to plant growth was evaluated using the ¹⁵N isotope dilution technique. All A. amazonense strains tested produced indoles, but only 10% of them showed high production, above 1.33 μM mg protein⁻¹. The nitrogenase activity also was variable and only 9% of isolates showed high nitrogenase activity and the majority (54%) exhibited a low potential. The inoculation of selected strains in rice under gnotobiotic conditions reduced the growth of root and aerial part when compared to the control, showing the negative effects of excess of phytohormone accumulation in the medium. However, in the greenhouse experiment, inoculation of strains of A. amazonense increased grain dry matter accumulation (7 to 11.6%), the number of panicles (3 to 18.6%) and nitrogen accumulation at grain maturation (3.5 to 18.5%). BNF contributions up to 27% were observed for A. amazonense Y2 (wild type strain). The data presented here is the first report that the PGPR effect of A. amazonense for rice plants grown under greenhouse conditions is mainly due the BNF contribution as measured by ¹⁵N isotope dilution technique, in contrast to the hormonal effect observed with other Azospirillum species studied.