钝裂银莲花花部综合特征及其繁育系统

钝裂银莲花(Anemone obtusiloba)是青藏高原东部常见的一种优势毒杂草,也是一种重要的草原退化指示植物,目前对其繁殖特性研究甚少.通过野外定位观察,运用TTC法、联苯胺-过氧化氢法、花粉-胚珠比(P/O)、杂交指数、人工授粉和套袋试验等方法,首次对该物种的花部特征及繁育系统进行了研究.结果表明:该物种单花花期为4～5 d,花雌雄异熟,雌蕊先熟,单花花粉活力和柱头可授期之间也存在一段时间的重叠,钝裂银莲花最佳授粉时间为一天中的12:00-14:00左右;按照杂交指数,其繁育系统属于异交、部分自交亲和,需要传粉者;P/O约为86,判断繁育系统类型为兼性自交;套袋试验显示,钝裂银莲花自然条件下存在无融合生殖现象,繁育系统为自交、异交亲和,以自交为主,但有时也需要传粉者;由此推断,该物种的繁育类型为混交的交配系统,即自交和异交并存,但倾向于自交.在长期的环境选择压力下,钝裂银莲花倾向于自交,可能是对不利环境条件的一种适应进化策略.     

耐热型西番莲品种‘钦蜜9号’花器官发育特征与繁育系统研究

为明确耐热型西番莲品种‘钦蜜9号’花器官发育进程特性和繁育系统类型，测定其花器官表型性状、花粉活性、柱头可授性、杂交指数和花粉/胚珠比。结果发现，‘钦蜜9号’花器官发育进程可分为：现蕾期-花冠发育期-雌雄蕊发育期-裂蕾期-开花授粉期-谢花期，时间持续25-27d，开花时间为下午13︰00-15︰00，单花开放时长约24 h，开花前3 d左右（花药即将开裂时）至裂蕾时柱头可授性最强；花粉数量为7.94x105个/花药，活性为90.11%，繁育系统类型为异交型，自交亲和，异交需要传粉者。这些特征为‘钦蜜9号’在35℃以上高温还能正常开花并结实提供了重要的基础条件。     

侧金盏花的花部特征与繁育系统观察

侧金盏花(Adonis amurensis)是东北地区常见的一种早春类短命植物,也是一种观赏性状优秀的园林草本种质资源。本研究针对黑龙江省哈尔滨市帽儿山老山人工林试验站的野生侧金盏花,对其花部综合特征、开花动态、授粉特性进行了研究。结果表明,侧金盏花花期为3-4月,花型大,单花花期持续6~10 d,花部具有吸引传粉者的特征。侧金盏花雌蕊先熟,开花过程中花药与柱头无空间间隔,杂交指数结果为3,花粉胚珠比为2 280,结合套袋试验结果,判定侧金盏花繁育系统为兼性异交,自交可孕,需要传粉者进行传粉。     

大花萱草‘金娃娃’的花器结构和繁育系统观察

通过观察,运用杂交指数、花粉/胚珠、花粉及柱头活力、坐果率等指标对大花萱草‘金娃娃’(Hemerocallis hybridus cv.‘Stella de oro’)的花部特征、开花动态及授粉特性等进行研究。在人工栽培条件下,金娃娃萱草5-9月开花,花苔分3～4次抽生,首次开花群体花期32 d,单苔花期9～16 d,单花花期1 d。雄蕊短于花柱,花药与柱头相差2.71 cm,在花朵开放的整个过程中雌、雄蕊的相对位置始终不变。开花前1 d的花粉活力最强,开花前1 d和开花当天的柱头具有较强的可授性。杂交指数为4,花粉/胚珠值为1 164,结合坐果率,可以判断其繁育系统属于兼性异交,部分自交亲和,需要传粉者。特殊的花部结构、缺少传粉者和花期短可能是金娃娃萱草结实率较低的原因。     

黄菖蒲花部特征及繁育习性研究

该研究旨在通过定点观察与人工授粉等方法,为黄菖蒲生殖生物学与杂交育种提供理论依据。对引种多年的黄菖蒲(Iris pseudacorus L.)的花器官特征、开花动态、花粉形态及活力、柱头可授性、繁育习性与访花昆虫进行了观察与研究,结果表明,黄菖蒲在南京地区为4月下—5月上开花,雌雄异熟;花粉活力与柱头可授性均为开花当天最强,随后下降;雌雄异位,开花过程中柱头向下弯曲,雄蕊始终短于柱头;花粉/胚珠比380.4,杂交指数为5。黄菖蒲的繁育习性为异交为主,部分自交亲和,需要传粉者,自然状态下存在花粉限制,不存在无融合生殖现象,黑纹食蚜蝇为潜在传粉者。     

暗紫贝母花器官特征及有性繁育系统研究

采用田间试验与显微镜检相结合的方法,对漳县人工栽培的暗紫贝母花器构造和传粉生物学进行研究,旨在揭示其花器官特征和有性繁育系统,为暗紫贝母的育种提供科学依据。结果表明,经鳞茎播种栽培3年的暗紫贝母植株单花顶生,偶见2花,花两性,初现花蕾绿色,花暗紫色,有淡黄色格纹,开花期5-6月,单花寿命6~8d,花钟形,同被花,花被6,2轮,离生雄蕊6枚,5枚紧围雌蕊,1枚外围,子房上位,柱头3裂,短裂片外露,毛状有分泌物。开花前柱头高于雄蕊,开放后雄蕊高出柱头,开花当天花粉量最大,活力最高并维持3d时间。花被长1.5cm的绿蕾柱头已具较强可受性。花药开裂与强柱头可受性同步,但后者持续期更长(6d以上)。单花花粉数约6000粒、胚珠数在160颗以上,花粉胚珠比(P/O)37.5,杂交指数(OCI)为4。传粉媒介为风媒和虫媒,访花者为蜂类、蝇类和蜘蛛,但数量极少,有性繁育系统应属于部分自交亲和,异交,需要传粉者。     

达乌里胡枝子的繁育系统及传粉生物学

为揭示达乌里胡枝子的传粉生物学特性,本文以山西省八个地区的野生达乌里胡枝子为供试材料,针对其繁育系统、传粉媒介等方面进行研究。结果表明：和顺居群的单花花粉量最多达到（8 750±1 946）粒·花^-1,而中阳的花粉量最少仅有（5 370±879）粒·花^-1。依照P/O值所测得的达乌里胡枝子繁育系统类型为专性异交。达乌里胡枝子的杂交指数为4,其繁育类型为存在自交和异交,需要传粉媒介传播花粉。昆虫访花行为会在10：00~11：00之间出现第一次访花高峰,在午后15：00~16：00出现第二次高峰,第一次高峰小于第二次。膜翅目昆虫如蜜蜂等传粉效果最为明显。国内外对达乌里胡枝子开花特性的研究较少,其繁育体系和授粉生物学尚未见报道。本研究结果不仅可为达乌里胡枝子的育种特性提供参考,也可为达乌里胡枝子的杂交育种和新品种培育提供理论和实践依据。     

三种豆科牧草繁育过程研究

本论文通过研究3种豆科植物紫花苜蓿,黄花苜蓿,扁蓄豆的开花习性及繁育系统—即花粉活力、寿命、柱头的活力、可授性、结实率、授粉率、传粉媒介进行了研究,结果表明:花粉活力平均值分别为紫花苜蓿77%,黄花苜蓿75%,扁蓄豆70%;花粉可育性为紫花苜蓿最高83.02%,其次黄花苜蓿80.57%,扁蓄豆为最低78.89%;紫花苜蓿、黄花苜蓿、扁蓄豆P/O值分别为5086.71,4786.57,4712.28。依据Cruden(1977)的标准:繁育系统为专性异交。结实率为紫花苜蓿72.88%,黄花苜蓿为67.19%,扁蓄豆为70.70%;3种植物的花期拜访昆虫5种以上,其中以蜂类,蝶类和蝇类为主,传粉昆虫的访花行为与当日开花数目,温度和光照条件密切相关。     

基于形态特征和SSR标记的斑茅繁殖策略的研究

本研究以收集自我国7个省的45份野生斑茅(Saccharum arundinaceum)为研究对象,在开放授粉条件下,通过测定斑茅的花粉与胚珠比(Pollen-ovule ratio,P/O)、杂交指数(Outcrossing index,OCI)以及基于简单重复序列(Simple sequence repeats,SSR)分子标记估计交配系统参数这3种方法,探究斑茅繁殖特性及其有性繁殖力的情况,为斑茅资源开发利用、杂交育种及繁殖技术提供基础依据。结果表明:斑茅P/O为5 897,杂交指数OCI为2;采用11对SSR引物对随机取样的15个斑茅半同胞家系共计1 158个子代进行交配系统参数估计,结果显示斑茅种群具有较高的异交率水平(t_m=0.864),多位点异交率和单位点异交率的差值不明显(t_m—t_s=0.012),亲本近交系数F大于0(F=0.318),表明斑茅以异交为主,并存在部分近交。综上所述,本研究初步认为斑茅的繁殖特性为异交为主、自交为辅的混合交配系统模式。     

喜盐鸢尾花部特征与交配系统研究

本研究采用定点观测与人工辅助授粉的方法,对种植8年的喜盐鸢尾（Iris halophila）花部特征、开花物候、花粉形态与活力、柱头可授性、交配系统与访花昆虫进行了观察与研究,旨在为喜盐鸢尾引种驯化与品种培育提供科学依据。结果表明：喜盐鸢尾5—6月开花,部分雌雄异熟;花粉活力开花当天最强,随后降低,与开花前后的天数呈现出显著的负相关关系（P<0.05）;柱头可授性比例开花第2 d最高,随后降低,与开花前后的天数呈现出显著的正相关关系（P<0.05）;雌雄异位,开花过程中雄蕊向上弯曲,柱头向下弯曲。花粉/胚珠比2 175.47,杂交指数为5,喜盐鸢尾的交配系统以异交为主,需要传粉者;自然状态下存在花粉限制,部分自交亲和,不存在无融合生殖,条蜂（Anthophora sp.）为潜在传粉者。     

Reproductive efficiency in grazing lactating dairy cows under a programmed reproductive management system

OBJECTIVE: To evaluate the effectiveness of a reproductive management program consisting of combinations of Ovsynch/TAI and prostaglandin (PG) F(2alpha) treatments in Holstein dairy cows under a pasture-based dairying system. DESIGN: Field trial. PROCEDURE: A total of 1177 cows in 8 commercial dairy farms were randomly allocated to control and treatment groups. Treatment group cows received one of two interventions depending upon the number of days postpartum (DPP) before the planned start of breeding. Cows more than 50 DPP by the planned start of breeding received the Ovsynch/TAI treatment, consisting of gonadotrophin releasing hormone (GnRH) - PGF(2alpha)- GnRH plus timed artificial insemination. Cows between 40 and 50 DPP received a PGF(2alpha) treatment followed by oestrus detection and, if the cow was not seen in oestrus, the cow received a second PGF(2alpha) 14 days later. Control cows were submitted to twice a day heat detection followed by artificial insemination. The experimental period was the start of the breeding season plus 21 days for cows over 50 DPP at the start of breeding, and was 40-61 DPP for cows that calved later and passed their voluntary waiting period after the start of the breeding season. RESULTS: Submission rate was higher for the treated group than for the control group (84.9% vs. 55.1%; P < 0.0001), as was the conception rate (51.0% vs. 46.1%; P < 0.03). Due to farm variations, pregnancy rate was similar in both groups (38.5% vs. 28.2%; P > 0.1). Within the treated group, conception rate and pregnancy rate of the cows inseminated after a PGF(2alpha) were higher than for timed artificial inseminated cows (51.4% vs. 32.6%; P < 0.001), and (37.8% vs. 32.6%; P < 0.001). CONCLUSION: A programmed reproductive management protocol may improve reproductive efficiency in dairy farms with seasonal breeding, by increasing submission and conception rates at the beginning of the breeding season and/or at the end of the voluntary waiting period. Fertility of cows bred after a PGF(2alpha) synchronised heat was greater than after an Ovsynch/TAI protocol.     

Seasonal infertility in Kenyan pig breeding units

Reproductive performance of 12 Kenyan pig breeding units (56-299 sows per unit) of similar feeding, genetics and health status were evaluated from October 2003 to October 2004 during hot and cooler periods. Sows during cooler months of the year (April to October, average temperature between 08:00 and 17:00: 25.2 +/- 2.2 degrees C) had shorter (P < 0.01) weaning to service intervals (7.9 +/- 2.2 days vs. 12.7 +/- 2.7 days, respectively), less (P < 0.01) regular returns to service (5.7 +/- 1.9% vs. 9.9 +/- 1.9%, respectively), higher (P < 0.01) farrowing rates (80.1 +/- 4.4% vs. 70.8 +/- 3.8%, respectively), and larger born (10.0 +/- 1.1 vs 9.1 +/- 1.7, P < 0.05) and weaned litter sizes (9.2 +/- 1.2 vs. 8.0 + 1.3, P < 0.05) compared with the time periods of high ambient temperature (November to March, between 08:00 and 17:00: 37.2 +/- 3.3 degrees C). It was concluded that a high ambient temperature is a risk factor for reproductive performance in pig breeding units.     

Digestibility of a complete ration in horses fed once or three times a day and correlation with key blood parameters

To determine the influence of feeding frequency on apparent digestibility and blood metabolites in horses, four geldings were fed a complete ration either once (at 08:00 h) or three times a day (at 08:00, 13:00 and 18:00 h). Horses were provided with a mixture of cereals and chopped alfalfa hay at maintenance level for energy supply, 344 kJ/kg BW(0.75) on a daily basis. After three weeks' adaptation, total amounts of faeces and urine were collected for five days, using collection harnesses. Serial blood samples were taken at -30, -15, 0, 5, 15, 30, 45, 60, 90, 120, 180, 240, 300, 360, 480 and 600 min after feeding and analysed for glucose, L-lactate, triglycerides (TG), non-esterified free fatty acids (NEFA) and triiodothyronine (T(3)). Apparent digestibility coefficients of dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), ash and nitrogen-free extract (NFE) were not significantly different (P>0.05) between the two feeding frequencies. Basal plasma glucose, plasma glucose curves and other plasma blood metabolites were not affected by meal frequency. The horses fed the whole ration in one morning feeding did not consume the entire meal at once, but spared feed for ingestion throughout the day, which may explain the lack of effect. Feeding frequency did not affect plasma glucose response (area under curve :AUC) (P=0.705), but AUC (glucose) was negatively correlated with CP (R(2)=0.76; P=0.005) and CF digestibility (R(2)=0.61; P=0.022). Further research is needed to clarify whether different endocrine responses or differences in passage rate can explain these correlations.     

Nitrogen balance and mineral excretion in growing male pigs injected with a human growth hormone-releasing factor analog.

A human growth hormone-releasing factor analog ([Desamino-Tyr1,D-Ala2,Ala15] hGRF(1-29) NH2) has been reported to reduce feed intake and increase growth and feed efficiency in a dose-dependent manner in growing pigs. The aim of this study was to determine the effect of this analog on nitrogen (N) balance and mineral excretion. Fifteen castrated male Yorkshire x Landrace pigs (45.9 +/- 1.4 kg) were randomly allotted to 2 groups: control (saline, n = 7) and GRF (6.66 micrograms/kg sc, TID, n = 8). The animals were injected for 20 consecutive days: feces and urine were collected during the last 10 d of injection. The animals had free access to water and food until satiety (approximately 15 min) at 07:00, 11:00, 15:00, 19:00, 23:00 and 07:00 h. The diet consisted of a hog fattening ration (18.0% crude protein). Blood samples were collected on the last day of the study by venipuncture. This analog increased (P < 0.05) insulin-like growth factor-1 and glucose serum concentrations and decreased (P < 0.05) serum urea nitrogen concentration and feed intake. The GRF-treated animals ingested less N, excreted less N in urine and feces to retain a similar amount of N than controls. The apparent coefficient of digestibility of the N has been slightly increased (P < 0.05) by GRF. Urinary excretion of P, K, and Cl decreased (P < 0.01) with GRF treatment. In conclusion, this GRF analog increased N digestibility and retention relative to N ingestion and reduced urinary N, P, K, and Cl excretion.     

圈养赤麻鸭繁殖期的行为日节律及时间分配

2011年4—6月,在徐州金桥珍禽有限公司,采用全日制瞬时扫描法对繁殖良好的一对赤麻鸭在繁殖期的行为日节律及时间分配进行了研究,并用独立样本￡检验进行了不同性别在繁殖各期行为的差异性分析。结果表明：繁殖的不同时期赤麻鸭行为时间分配存在明显的性别差异。繁殖前期雌雄赤麻鸭之间的筑巢行为差异极显著（P〈0．01）,警戒行为差异显著（P〈0．05）。繁殖中期孵化行为由雌性赤麻鸭单独承担,雄性主要负责在巢边警戒,雌雄之间的趴卧、孵化及警戒行为差异极显著（P〈0．01）。繁殖后期雌雄行为差异不显著（P〉0．05）,2只赤麻鸭几乎形影不离。赤麻鸭繁殖期行为呈现一定的日活动节律,采食行为集中在上午和下午的喂食时间7：00～8：00及16：00～17：00这2个时间段内,孵化行为所占比例最低,此时雌性赤麻鸭出巢取食;一天中,休息行为在中午呈现一个高峰;警戒行为在清晨达到最高峰。     

Energy expenditure of Angora bucks in peak breeding season estimated with the doubly-labeled water technique

We used the doubly-labeled water (DLW; 2H2(18)O) method to compare total energy expenditure (TEE) of Angora bucks and wethers over a 15-d period during peak breeding season. Four bucks (57+/-3 kg) and four wethers (45+/-2 kg) were fitted with marking harnesses to measure sexual activity and allocated pairwise to one of four breeding groups (n = 30 does/group). Subjects were infused i.v. with 2H2(18O) that provided 200 mg 2H2O and 250 mg H2(18)O/kg BW. Blood samples were collected over a 15-d period, with 3- to 4-d intervals for isotope enrichment measurements. Total DLW-derived energy expenditure (TEE) was similar (P = .55) between bucks and wethers (2,578 vs 2,365; SE 239 kcal/d). Large variation was observed among wethers in TEE, courtship, and attempted mountings. Total energy expended corrected for that in mohair production (CTEE) tended (P = .09) to be greater in sexually active wethers (133+/-8 kcal ME/[kg BW.75 x d(-1)]; n = 3) than in bucks (110+/-7 kcal ME/[kg BW.75 x d(-1)]; n = 4). Energy expended on activity (EEa) by these wethers was highly correlated (r = .98) with the number of does marked, which may explain high variability among wethers in EEa. Bucks marked more does (18+/-1; P < .05) than wethers (8+/-3), but a weak relationship (r = .36) existed between number of does marked and EEa, suggesting individuality in style and persistence while courting. In Angora bucks, CTEE during the breeding season was 9% greater than the maintenance energy requirement. In conclusion, breeding activities in single-buck breeding groups did not markedly increase energy requirements of Angora bucks.