红凤菜扦插繁殖技术研究

为了探讨红凤菜扦插繁殖的适宜条件,采用不同基质、不同成熟度插条及不同萘乙酸(NAA)浓度进行三个因素随机区组试验,萘乙酸、插条成熟度和基质组成对红凤菜插条生根数量均有显著影响,其中萘乙酸处理对红凤菜插条生根数量的影响最大,枝条成熟度其次,扦插基质影响较小,结果表明扦插生根的最佳组合为:1 000 mg/kgNAA×幼嫩枝条×泥炭土∶珍珠岩=1∶1,NAA极显著地促进插条生根,数量增多,同时又极显著地抑制根的伸长。     

Presumable role of plasmodesmata in floral signal transduction in shoot apical meristems of rudbeckia and perilla plants

The number of plasmodesmata was calculated per 1 μm of cell wall length in the central and medullar zones of shoot apical meristems (SAM) in the course of floral transition in a long-day (LD) plant Rudbeckia bicolor Nutt. and a short-day plant Perilla nankinensis Lour. Under the day length unfavorable for flowering (control), the numbers of plasmodesmata differed in the central and medullar zones of SAM, which produce the reproductive organs and stems, respectively. Besides, the numbers of plasmodesmata in the central zone of perilla SAM considerably differed between the anticlinal and periclinal cell walls of the first and second cell layers. Following the photoperiodic induction (PI) with eight LD in rudbeckia and twelve SD in perilla favorable for floral transition, the numbers of plasmodesmata considerably increased in the anticlinal and periclinal cell walls of the first and second cell layers of the central zone; meanwhile in the medullar zone, the numbers of plasmodesmata dropped down following PI. These data show that floral transition presumably involves the activation of cell-to-cell interactions and enhances the signal transduction in SAM.     

Facultative response to a kleptoparasite by the cooperatively breeding pied babbler

In many cases of interspecific kleptoparasitism, hosts developdefensive behaviors to minimize the impact of kleptoparasites.Because vigilance and defensive behaviors are often costly,selection should favor hosts that adjust the amount of investmentneeded to minimize losses to kleptoparasitism. However, examplesof such facultative responses are rare. Here, we investigatethe response of cooperatively breeding pied babblers (Turdoidesbicolor) to the drongo (Dicrurus adsimilis), an avian kleptoparasitethat regularly follows pied babbler groups, often giving alarmcalls to alert the group to predators but also occasionallygiving false alarm calls in order to steal food items. We showthat pied babbler response to drongos varies markedly accordingto babbler group size. In small groups, where there are fewindividuals available to act as sentinels, babblers sentinelless when a drongo is present and respond strongly to drongoalarm calls. However, in large groups, where there are manyindividuals available to participate in predator vigilance,babblers sentinel more often when a drongo is present, rarelyrespond to drongo alarm calls, and aggressively displace drongos,with a consequent decline in the number of successful kleptoparasitismevents. This behavior represent a facultative response to akleptoparasite according to the costs versus benefits of toleratingtheir presence.     

Variable postfledging care in a cooperative bird: causes and consequences

Prolonged postfledging care is a commonly observed behaviorin many cooperatively breeding species and has been shown toprovide young with both survival and developmental benefits.However, the causes of intraspecific variation in postfledgingcare and the consequences of this variation on the developmentof young remain unclear. Here we investigate factors affectingthe duration of postfledging care in the cooperatively breedingpied babbler (Turdoides bicolor). We show that the durationof care is variable (40–97 days) and is determined primarilyby the cost of care. Adults in groups with a low adult:fledglingratio were unable to maintain body mass during the period ofchick provisioning and subsequently ceased care of young earlier.This had a strong influence on offspring development: fledglingsthat received longer periods of care attained higher foragingefficiency and body mass than their counterparts at 6 monthsof age. The duration of postfledging care also had long-termeffects, with individuals that received longer periods of postfledgingcare more likely to successfully disperse from their natal group.This had important fitness implications as successful dispersersbecame reproductively active at an earlier age than their "failed-disperser"counterparts. These findings highlight the importance of consideringlong-term influences when assessing the benefits of prolongedpostfledging care on offspring fitness and development in cooperativesocieties.     

高粱体胚发生的组织细胞学观察

以Sb33高粱非胚性、胚性愈伤组织和体胚为材料,用传统石蜡切片法对各组织材料进行组织化学染色,对高粱胚性与非胚性愈伤组织以及体胚进行组织细胞学观察。结果表明：高粱非胚性愈伤组织无淀粉粒积累,高粱胚性愈伤组织淀粉粒积累较多,而与胚性愈伤组织相比,高粱体胚淀粉粒积累更多,这说明淀粉粒的积累与高粱体细胞的胚胎发生密切相关。此外,高粱可通过鱼雷胚基部产生球形胚的方式实现体胚的增殖,高粱离体再生途径以体细胞胚发生为主,并同时存在少量器官发生途径。在高粱体细胞胚胎发生中,外起源和内起源同时存在。本研究为高粱体细胞胚胎发生提供细胞学理论基础。     

Crop photoperiodism model 2.0 for the flowering time of sorghum and rice that includes daily changes in sunrise and sunset times and temperature acclimation

Background and AimsDaylength determines flowering dates. However, questions remain regarding flowering dates in the natural environment, such as the synchronous flowering of plants sown simultaneously at highly contrasting latitudes. The daily change in sunrise and sunset times is the cue for the flowering of trees and for the synchronization of moulting in birds at the equator. Sunrise and sunset also synchronize the cell circadian clock, which is involved in the regulation of flowering. The goal of this study was to update the photoperiodism model with knowledge acquired since its conception.MethodsA large dataset was gathered, including four 2-year series of monthly sowings of 28 sorghum varieties in Mali and two 1-year series of monthly sowings of eight rice varieties in the Philippines to compare with previously published monthly sowings in Japan and Malaysia, and data from sorghum breeders in France, Nicaragua and Colombia. An additive linear model of the duration in days to panicle initiation (PI) and flowering time using daylength and daily changes in sunrise and sunset times was implemented.Key ResultsSimultaneous with the phyllochron, the duration to PI of field crops acclimated to the mean temperature at seedling emergence within the usual range of mean cropping temperatures. A unique additive linear model combining daylength and daily changes in sunrise and sunset hours was accurately fitted for any type of response in the duration to PI to the sowing date without any temperature input. Once calibrated on a complete and an incomplete monthly sowing series at two tropical latitudes, the model accurately predicted the duration to PI of the concerned varieties from the equatorial to the temperate zone.ConclusionsIncluding the daily changes in sunrise and sunset times in the updated photoperiodism model largely improved its accuracy at the latitude of each experiment. More research is needed to ascertain its multi-latitudinal accuracy, especially at latitudes close to the equator.     

花叶芋(天南星科)的花器官发生

利用扫描电镜首次观察了天南星科花叶芋(Colocasia bicolor) 的花器官发生过程。花叶芋的肉穗花序由无花被的单性花构成, 雌花发生于花序基部, 雄花发生于花序上部, 中性花位于花序中间部位。雄花: 3 或4 个初生雄蕊原基轮状发生, 随后每个初生原基一分为二, 形成6或8个次生原基; 一部分次生原基在其后的发育过程中融合, 形成5 或7 枚雄蕊; 雄花发育过程中未见雌性结构的分化; 花药的分化先于花丝; 雄蕊合生成雄蕊柱。雌花: 合生心皮, 3或4个心皮原基轮状发生, 未见雄性结构的分化。中性花来源于雌雄花序过渡带上, 属于雄蕊原基的滞后发育以及发育成熟过程中的退化; 与彩叶芋属(Caladium)不同, 此过渡区未见畸形两性花。初生雄蕊原基二裂产生次生原基的次生现象在目前天南星科花器官发生中显得比较特殊, 同时初步探讨了次生原基的融合方式。     

华模蛛科——采自中国的蜘蛛目一新科(蛛形纲,蜘蛛目)

记述了采自我国云南西双版纳雨林的1新科,华模蛛科Sinopimoidae fam.nov.,1新属,华模蛛属Sinopimoa gen.nov.,1新种,双色华模蛛Sinopimoa bicolor sp.nov..模式标本保存在中国科学院动物研究所.     

诱导突变高粱愈伤组织初探

本实验以突变体高粱的不同外植体 ,成熟种子、成熟胚、茎尖、和幼胚等为材料 ,诱导愈伤组织。经出愈率和生长状况观察 ,幼胚最好 ,成熟胚较好 ,成熟种子和茎尖略差。对于茎尖 ,2 ,4 D与KT搭配较好 ;成熟胚而言 ,不加细胞分裂素 ,加适量 2 ,4 D浓度效果较好 ,幼胚愈伤组织诱导和培养不需要细胞分裂素 ,加浓度为 2 .0mg/L2 ,4 D效果较好 ;若加KT ,同时要提高 2 ,4 D浓度 ;成熟种子培养 ,需要细胞分裂素     

Cadmium phytoextraction from loam soil in tropical southern China by Sorghum bicolor

The cadmium (Cd) uptake characteristics by Sorghum bicolor cv. Nengsi 2# and Cowley from the acidic sandy loam soil (pH = 6.1) during the entire growth period (100 days) were investigated in pot outdoors in a tropical district of southern China, Hainan Island. The Cd-spiked levels in soil were set as 3 and 15 mg/kg. Correspondingly, the available Cd levels in soil extracted by Mehlich III solution were 2.71 and 9.41 mg/kg, respectively. Basically, two varieties in a full growth period (100 days) did not show a significant difference in their growth and Cd uptake. Under high Cd stress, the plant growth was inhibited and its biomass weight and height decreased by 38.7–51.5% and 27.6–28.5%, respectively. However, S. bicolor showed higher bioaccumulation capability of Cd from soil to plant [bioconcentration factor (BCF)>4], and higher transfer capability of Cd from roots to shoots [translocation factor (TF)>1] under high Cd stress; Cd contents in the roots, stems, and leaves of S. bicolor reached 43.79–46.07, 63.28–70.60, and 63.10–66.06 mg/kg, respectively. S. bicolor exhibited the potential phytoextraction capability for low or moderate Cd-contamination in acidic sandy loam soil.