试论小麦育种家种子特点及其生产和利用

论述了小麦育种家种子的特点和它的两种主要生产方法,并对其在种子生产中的地位作用、繁育体制等问题进行了分析探讨。     

育种家种子的特点及其生产和保存方法

为克服“三圃制”的不足,国内一些专家研究提出了“四级种子生产程序”、“一圃制”等农作物良种繁育新技术,这些方法繁育生产各级种子的起点均是育种家种子。本文论述了育种家种子的概念、特点,并对不同作物生产和保存育种家种子的方法等问题进行了探讨,为农作物的良种繁育提供参考依据。     

四级种子生产程序及其应用

我国长期沿用的农作物良种繁育方法“三圃制”，存在许多弊端，已不适应农业发展形势的需要。在多年农作物良种繁育实践中研究总结出的“四级种子生产程序”，能有效地保持优良品种纯度和种性。节约种源，减少世代，有利于实现种子标准化，延长使用年限。经济简便，解放了生产力。使育、繁、推一体化，形成了合力。该方法以现代遗传学作为理论基础。几年来，已迅速在河南省大部分地市推广应用，效益显著。     

论甘薯四级种子生产程序及繁育供种体系

利用20世纪50年代沿袭下来的“三囿制“进行甘薯种薯生产，已难以适应现代化种业的发展。为此，本文结合甘薯生产实践，借鉴农作物良种繁育的最新成果，提出了甘薯育种者种子→原原种→原种→良种四级生产程序及关键技术，同时也探讨了甘薯繁育供种体系和各级种薯的生产规模。     

应用“四级种子生产程序”搞好“育、繁、推”一体化

本文概述了四级种子生产程序的应用，促进了“育、繁、推”一体化，从而提高了成果的转化率。     

育种家种子的生产与保存

根据各类农作物遗传变异特点和繁育方式的不同，介绍育种家种子的不同生产方法以及田间种植保存方法。并对育种家种子的室内保存技术进行了探讨。     

小麦种子繁育的一般原则和通用程序

小麦（Triticum aestivum L.）是我国的重要粮食作物,种子繁育是小麦产业化的关键环节。我国现行小麦种子繁育程序包括三圃制、二圃制、一圃制、四级种子生产、株系循环选择、一圃三级种子生产等六种。为了适应现代小麦产业化的需要,在分析现有种子繁育程序的基础上,根据小麦遗传特征,提出小麦种子繁育的一般原则和通用程序,供小麦育种、繁种、推广者参考。     

小麦生产用种原种化的实践与探索

目前,我国将小麦种子划分为育种家种子、原原种、原种、良种四级.其中,育种家种子和原原种一般都作繁殖材料,而原种既可作为繁育材料,也常用于大田生产;良种则主要用于大田生产,国际上一般称为登记种子或大田用种.     

小麦种子生产与经营的特点及其对策分析

与其他主要农作物相比,小麦种子生产与经营具有品种区域性强、种子需求量大、纯度要求高、生产周期长、经营时间短等特点。在小麦种子生产与经营中,应注意小麦品种的区域适应性,重点利用广适应性品种,注意防杂保纯,实施小麦生产用种原种化,推广种子生产的免去杂技术和实行种子联繁联营。     

一圃三级小麦种子生产技术的实践基础

该技术交重复繁殖和循环选择两种种子生产方法有机地结合在一起，以国外农业发达国家的种子生产方法和我国种子生产的先进技术为实践基础，解决了当前良种繁育技术中存在的问题，是适合我国现阶段物质、技术条件的种子生产先进技术之一，已在河南省小麦种子繁育中推广应用。     

开放型小麦种子生产技术体系研究

目前我国现行的小麦良种生产体系已不能适应新形式下的农业生产需求,因此必须以市场为导向,坚持科学发展观,与时俱进．充分利用我国地域辽阔、生态类型多样等特点．积极探索并建立适合我国小麦种子生产的多形式、多渠道、多方位、多区域的开放型小麦种子生产新体系。这对于实现种子生产产业化,建立现代种子生产体系及与国际种业市场接轨都有重要的战略意义和现实意义．也为实现农业科研成果向产业化快速转化及加快小麦新品种推广探索一条新路．     

Chemically induced sterility in wheat for hybrid seed production

Summary The gametocidal effects of RH-531, RH-532, and RH-2956 were studied with three rates and times of foliar application on two spring wheat (Triticum aestivum L.) varieties, Anza and Yecora 70. RH-531 and RH-532 applied at or before booting stage caused rather large reduction in plant height while RH-2956 had a small effect on height. Application of any of the three chemicals on Anza at meiotic stages reduced self-pollination (SP) fertility by 97–99%. If 90% SP fertility reduction is acceptable, the application time could vary from premeiosis to postmeiosis for Anza. Yecora 70 was less sensitive than Anza to gametocide treatments. The lowest SP fertility obtained in Yecora 70 with RH-531, RH-532, and RH-2956 was by treatment at booting (4 kg/ha), at premeiosis (2 kg/ha), and heading (8 kg/ha), and the corresponding SP fertility reductions were 74, 89, and 71%. Pollen stainability-determined by aceto-carmine, IKI, and Alexander's stains-was not affected by gametocide treatment and was not useful in evaluating sterility induced by these chemicals. For the RH-531-treated Anza and Yecora 70 and the RH-532-treated Anza, more than 94% of the seeds produced by open-pollination on treated plants were from self-or sib-pollination as determined by progeny testing. However, RH-532-treated Yecora 70 and RH-2956-treated Anza and Yecora 70 did result in more crossed seeds, with a maximum of 20% outcrossing. It was believed that spike compactness induced by the chemicals and the related poor flower opening were the major limitations for outcrossing. Artificial pollinations made to the test varieties showed that RH-531 induced both male and female sterility and was undesirable for practical use. RH-532, however, could be applied at the booting stage to avoid severe female sterility, and RH-2956 clearly was the best of the three chemicals, with the female fertility very close to those of the untreated checks of both Anza and Yecora 70. Of the three chemicals, RH-2956 gave the highest percentage of hybrid plants in the progeny of hand-or open-pollinated spikes. Its practical use for hybrid seed production, however, will depend largely on improvement of methods to increase cross pollination in wheat.     

Temperature effects on seed germination and expression of seed dormancy in wheat

Because preharvest sprouting decreases quantity and quality of wheat grain, researchers need effective protocols to assess response to preharvest sprouting conditions. The aim of this study was to determine which temperature gives the greatest difference in seed germination and expression of seed dormancy in 10 spring wheat genotypes. The genotypes were grown in the field near Swift Current, Saskatchewan in 2000 in a randomized complete block with four replicates. Seed samples were harvested at approximately 25% moisture content (wet weight basis) and dried to 12% moisture content with minimal after-ripening. Germination was under controlled environment at temperatures of 10, 15, 20 and 30 °C in darkness. A weighted germination index (WGI) was calculated. The analysis of WGI, for each temperature, showed highly significant (p ≤ 0.01) genotype effects on germination. Most genotypes decreased in WGI (increased dormancy) as temperature was increased from 10 to 30 °C. The greatest differences in seed germination tended to be at 15 °C and 20 °C. The level of seed dormancy depended on the genotype and germination temperature. This revised version was published online in August 2006 with corrections to the Cover Date.     

The effects of cis-trans ABA on embryo germination and seed dormancy in wheat

Pre-harvest sprouting of wheat grain can cause economic losses especially in cultivars with low levels of seed dormancy. The aim of this study was to determine genotype differences in embryo sensitivity to germination in response to exogenous (+/–) cis-trans ABA treatments at different concentrations. Six white and four red seed-colored bread wheat genotypes that differed in dormancy were grown in a field near Swift Current, Saskatchewan in 2000 as a randomized complete block design with four replicates. The seed samples from this experiment were germinated in a controlled environment at 20 °C without light. The exogenous ABA treatments were 0 μM – whole seed (control), 0 μM-embryos, 25 μM – embryos and 50 μM – embryos. The ABA experiment was a factorial design with four randomized complete blocks with four ABA treatments in all combinations with the ten genotypes. A weighted (by day) germination index (WGI) was calculated for each genotype in each ABA treatment. Genotypes differed in response to ABA. The genotypes, ABA concentration and genotype by ABA concentration interaction effects were significant (p ≤ 0.05). Excised embryos showed significantly decreased dormancy in most of the experimental genotypes. The addition of exogenous ABA enhanced embryo dormancy of most genotypes. This revised version was published online in August 2006 with corrections to the Cover Date.     

贵州省林木良种繁育探讨

本文回顾了贵州省林木育种工作30多年来所取得的成绩,概述了全省林木良种工作现状.着重分析了现阶段全省林木良种工作中急需解决的主要问题,并对林木良种工作的提高提出了建议.     

新型植物生长调节剂在小冬瓜制种生产上的初探

应用新型植物生长调节剂对小冬瓜进行生产应用试验，研究表明：（1）新型植物生长调节剂3ml／L和4ml／L处理生长期小冬瓜，小冬瓜平均瓜长、平均横径、平均单瓜重，小区产量分别比对照增加了10．97％，11．15％，21．9％，22．2％和11．37％，9．16％，24．3％，24．4％；说明新型植物生长调节剂可显著提高小冬瓜产量；（2）新型植物生长调节剂3ml／L和4ml／L处理小冬瓜，小冬瓜蛋白质含量、维生素C含量、可溶性固形物含量、瓜肉厚度分别比对照提高了0．12％、1．57％、0．21％、31．6％和0．11％、1．41％、0．17％和29．7％。说明新型植物生长调节剂能改善小冬瓜品质。     

Effect of germination, seed abrasion and seed size on polyphenol oxidase assay activity in wheat

Polyphenol oxidase (PPO) is one of the major enzymes responsible for browning of wheat food products. Wheat cultivars differ in PPO activity and plant breeders wish to select germplasm and cultivars with low PPO activities. Prior to harvest, seeds may be exposed to conditions conducive to preharvest sprouting and mechanical damage may occur during harvesting and subsequent handling. Sprouting, mechanical damage and seed size may affect PPO assay activity and therefore impinge upon the breeder's ability to accurately select low PPO genotypes. The effects of incipient germination, mechanical abrasion and seed size on PPO assay activity were investigated using the cultivars ‘Klasic’(hard white spring, high PPO), ‘Penawawa’(soft white spring, high PPO) and ‘ID377s’(hard white spring, low PPO). The influence of embryo vs. distal portions of the seed on PPO assay activity was also examined. PPO activity was assayed with constant mixing using L‐3,4‐dihydroxyphenyl alanine (L‐DOPA) substrate at pH 6.5 at room temperature; absorbance of the reaction solution was measured at 475 nm. There was no change in PPO assay activity for seeds imbibed in water for up to 8 h. PPO assay activity increased in seeds imbibed from 8 to 16 h, and then gradually declined with increasing imbibing time. PPO assay activity initially increased as a result of mechanical abrasion but then gradually declined with increasing abrasion time. Large seeds had a higher total PPO assay activity than small seeds, but the difference in activity was not proportional to seed weight. There was only a slight difference in PPO assay activity between half‐seeds with or without the embryo. Overall, PPO assay activity in dry seeds was stable and exposure of seeds to injury and moisture did not make any significant change in PPO assay activity among the cultivars or their relative rankings.     

苯酚染色测定小麦种子纯度的试验与应用

应用苯酚染色法对不同特征特性的小麦品种种子进行了颜色分类鉴定，并测定了温麦8号小麦种子的纯度，对苯酚染色法的应用效果进行了分析和讨论，提出了在实际鉴定工作中应注意的问题。