板栗不同品种花粉育性研究

对19个板栗品种的花粉育性的两个方面(花粉萌发率、花粉管生长特性)进行了测定 分析,发现板栗花粉的萌发率一般高于65%,以70%～90%区域内分布为最多,高于90%和低 于70%的品种较少。花粉管生长在花粉萌动后的20min中伸长最快,而后逐渐趋于平稳。一 定浓度的蔗糖溶液有助于花粉管的生长,10%、20%蔗糖浓度均能显著提高花粉管伸长速度。     

玉米纸筒秧苗移栽机的研究

玉米纸筒秧苗移栽是一项有别于传统直播的新型栽培技术,采用人工大棚内纸筒育苗、适龄秧苗移栽的方式有效提高玉米生产期,彻底解决春季干旱、病虫害对玉米产量和品质的影响,增产增收效果明显。玉米纸筒育苗移栽机克服人工移栽劳动强度大、移栽效率低和作业质量不标准的显著缺点,为玉米标准化、机械化、自动化提供机具载体保证。该机设计了具有自动给苗、剔苗、补苗功能的上秧摆苗机器人系统,可实现纸筒秧苗的自动抓取分离及码放,秧册自动进给,自动剔除无苗、弱苗纸筒及加速补苗等功能,整机采用全液压驱动系统及以PLC为核心的自动控制系统。该机将自动取秧、数字识别无苗纸筒并自动剔除,有苗纸筒带式水平输送和垂直接力输送、垄上破茬开沟、零速投苗栽植、垄型整理、滤水覆土等作业有机地整合在单台移栽机上一次完成,大大提高了作业效率,实现玉米纸筒秧苗移栽作业的标准化、机械化和自动化。     

机组导叶关闭规律对相继甩工况的影响

针对“一洞两机”布置型式的抽水蓄能电站,基于瞬变流理论和特征线法,采用多种关闭规律对实际工程进行数值模拟;分析不同关闭规律对相继甩负荷工况时尾水进口最小压力产生影响的内在机理,得到针对尾水进口最小压力的最优关闭规律求解方法.结果表明不同关闭规律可决定尾水进口最小压力出现在先甩机组还是后甩机组工况.采取适当的先慢后快关闭规律可以使得2台机组在各自最不利时刻点的尾水进口最小压力近似相等,并优于其他关闭规律.求解该关闭规律步骤：初步选择一种两段折线关闭规律,若后甩机组尾水进口最小压力小于先甩机组的,则应将关闭规律做调整：将第1段折线斜率改小,将第2段折线斜率改大;若后甩机组尾水进口最小压力大于先甩机组的,则反之,直至2台机组尾水进口最小压力近似相等为止.     

Fruit set evaluation for self-compatibility selection in almond

Self-compatibility was assessed in 19 almond selections by genetic and physiological means, such as PCR with specific primers for the S_f allele, pollen tube growth, and fruit set after self-pollination and in bagged branches. Although all genotypes possessed the S_f allele and showed a similar pollen tube growth after self-pollination than after cross-pollination with cross-compatible pollen, fruit sets showed a different behaviour between years, ranging from 16.2 to 24.7%, as well as between treatments, with the highest after self-pollination. The differences between genotypes could be due to the genetic constitution of each genotype, where inbreeding may reduce set by the accumulation of deleterious genes in different members of a progeny. Flower morphology may also affect sets in bagged branches. Thus, in addition to bud density, flower sterility, pollination success and environmental conditions, other traits must be taken into account when evaluating yield in self-compatible almond cultivars, such as the inbreeding effect and the effective autonomous self-pollination.     

切割花柱方式对亚百系内杂交花粉管生长和结实的影响

用常规柱头授粉和切割不同长度花柱4种授粉方式对亚百系内杂交的花粉管生长和结实情况进行了研究.结果表明:同一系内各组合亲和性存在差异,亲和性较好的组合为"金色号角×多安娜"、"普瑞头×索莱尔",次之为"多安娜×普瑞头","金色号角×普瑞头","普瑞头×多安娜"为不亲和组合;同一系内组合中,采用常规柱头授粉比切割花柱授粉得到胚的比例高,所有组合花粉管均能进入子房,而且随着切割花柱长度的增加,花粉管在花柱中及进入子房的量是依次递减的,种子数目与花粉管的生长情况呈正相关;果实膨大系数不能反映果实是否结籽;所有组合中都存在胚囊不亲和现象,形成了无胚仅有胚乳的种子.     

蔗糖、钙和硼对榆叶梅花粉离体萌发及花粉管生长的影响

研究了不同浓度蔗糖、钙(CaCl2)和硼(H3BO3)对单瓣榆叶梅(Prunus triloba var. simplex)和重瓣榆叶梅(Prunus triloba var. plena Dipp.)离体条件下花粉萌发和花粉管生长的影响.结果表明:5%～10%的蔗糖不利于花粉的萌发和花粉管生长,15%～30%的蔗糖能够提高花粉的萌发率和花粉管生长长度,其中25%的蔗糖为最适浓度,单瓣和重瓣榆叶梅相差不大,二者平均花粉萌发率和花粉管长度为38.72%和489.6 μm.0.01%～0.07%的外源钙可以显著促进榆叶梅花粉的离体萌发和花粉管的生长,0.03%作用最大.0.01%的硼对单瓣榆叶梅,0.01%～0.03%的硼对重瓣榆叶梅花粉萌发和花粉管生长有显著的促进作用,重瓣榆叶梅比单瓣榆叶梅更需要外源硼的补充.     

Laparoscopic‐assisted tube cystotomy for urethral rupture in a foal

A 10‐day‐old Tennessee Walking Horse colt was hospitalised due to a pelvic urethral tear. After 2 unsuccessful attempts to repair the tear by primary closure, the colt underwent perineal urethroplasty and laparoscopic‐assisted tube cystotomy which permitted complete urine diversion and allowed the urethral tear to heal completely.