西杂哺乳犊牛补饲方法试验报告

本研究选用４４头１０日龄西杂二代犊牛，随机分成试验组和对照组，试验组定时定量补饲饲配合饲料，且喂以干麦草和混合料，研究犊牛增重效果。结果表明，在补饲人，试验组和对照组的平均日增重分别为８３８和４８７ｇ；头均补饲草料量无显著差异；头均盈利分别为７８８和４７６元。试验组件和出栏时间比对照组提前增年至一年。西杂占在哺乳期积累补饲培育，具有良好的增重效果和明显的经济效益。     

Southern pollen sired more seeds than northern pollen in southern seed orchards established with northern clones of Pinus sylvestris

Abstract

Contamination by southern pollen is a considerable problem in Scots pine (Pinus sylvestris L.) seed orchards established with northern clones. This study investigated whether the contamination was due to the competitive superiority of southern pollen by carrying out competition trials using mixtures of pollen from northern and southern populations of Scots pine. Trials were performed in a southerly seed orchard established with clones originating from northern populations. Seed paternity (siring) was determined through the analysis of allozyme variation. Southern genotypes sired significantly more seeds (76%) than their northern competitors and across all mixed-pollen crosses. Maternal genotype had no effect on seed siring success. The mean flower abortion rate was lower in southern pure-pollen crosses and mixed-pollen crosses than in northern pure-pollen crosses. The results show that local pollen may induce high levels of background pollination in southern seed orchards composed of northern genotype grafts. These results must be taken into account when aiming to produce suitable reforestation material for northern areas.     

杂交小麦强优势组合选配分析

选用8个表现突出的杂交组合,以小偃22作对照,从亲本和杂种一代产量性状、株型、株高、抗病性等农艺性状角度对其组合选配模式进行了分析。结果表明：8个组合在产量性状上均表现出正向的杂种优势。产量构成因素中以千粒重的优势为最大,其次为穗数和穗粒数;多穗型亲本与早熟大穗亲本型组配,且双亲株高在75～80cm左右,株型紧凑,抗病,较容易选配出理想的强优势组合,为杂种小麦生产实现产业化提供依据。     

加拿大披碱草×野大麦三倍体杂种F1加倍植株的染色体及育性鉴定

对加拿大披碱草与野大麦2个四倍体亲本杂交产生的三倍体(2n=3x=21)属间杂种F1的自然加倍植株、自然加倍植株F1代及秋水仙素诱导加倍植株的染色体数目及配对构型、花粉育性、结实性进行了鉴定。结果显示:自然加倍植株、自然加倍植株F1代和秋水仙素诱导加倍植株的RTC染色体数目均为42条,即为六倍体(2n=6x=42);其PMCMⅠ平均染色体配对构型分别为0.04Ⅰ 20.96Ⅱ、0.03Ⅰ 20.98Ⅱ和0.03Ⅰ 20.97Ⅱ,配对行为规则;它们的花粉可育率分别为84.97%、94.08%和90.21%,自然结实率分别为77.51%、83.87%和80.13%。证明该属间杂种F1染色体已加倍,且染色体加倍植株的育性已得到恢复。     

大白菜和羽衣甘蓝种间杂交研究

以改良萝卜胞质不育大白菜为母本 ,以甘蓝型油菜为桥梁种进行杂交 ,获得了较多的种间CMS杂种 ;又以此种间CMS杂种为母本 ,以 7个羽衣甘蓝品种为父本进行第 2次杂交 ,平均亲和指数仅为 0 .0 0 1;采用离体胚培养 ,使 14d胚龄第 2次种间杂合幼胚在MS +BA 2mg·L-1+NAA 0 .0 5mg·L-1+蔗糖 30g·L-1的培养基上发育成小植株。     

Production of polyhaploids of hexaploid wheat using stored pearl millet pollen

The effects of drying and freezing on viability of pearl millet pollen were examined with the aim of using stored pollen in polyhaploid production of hexaploid wheat. Freshly collected pollen of pearl millet line NEC 7006 with 55% water content, germinated at a frequency of 80%. Pollen that was dried for two hours to 6% water content showed 50% germination frequency and maintained similar frequencies after the freezing process. In crosses of hexaploid wheat variety Norin 61 with fresh pearl millet pollen, embryos were obtained at a frequency of 27.6%. In crosses with pollen stored at -196 °C, -80 °C and -20 °C for one month, embryo formation frequencies ranged from 27.5 to 17.4%. After five and twelve months of storage, the frequencies ranged from 29.7 to 14.6% at storage temperatures of -196 °C and -80 °C, and from 8.0 to 3.2% at -20 °C, indicating significant differences among storage temperatures. However, no significant frequency difference was found among pollen water contents at the time of collection. All plants regenerated from crosses with pearl millet pollen stored for five months were wheat polyhaploids. These results suggest that stored pearl millet pollen is an efficient medium for producing polyhaploids in hexaploid wheat. This revised version was published online in August 2006 with corrections to the Cover Date.     

Diallel analysis of four resistance components to Septoria tritici in six crosses of wheat (Triticum aestivum)

Four resistance components, i.e. incubation period, latent period, maturation period and pycnidial coverage, were studied in a diallel cross of four wheat cultivars differing in susceptibility to Septoria tritici. Inoculations and evaluations were carried out at the fourth leaf stage for two years. A combined ANOVA for both years exhibited a significant interaction between crosses and years for maturation period. A separate ANOVA for each year was done for this trait. The combined ANOVA showed that crosses were significantly different for incubation, latent period and pycnidial coverage. Cross effects were also significant for maturation period in each year for the separate ANOVA. Year effects were significant for latent period and maturation period. General combining ability (GCA) was significant and preponderant for incubation period, latent period and pycnidial coverage. For maturation period, the separated ANOVA showed the significance of the GCA for both years. Specific combining ability (SCA) was significant for incubation and pycnidial coverage and for maturation in one year. The preponderance of the additive genetic variance for all traits indicates the possibility of selecting for them in order to obtain improved cultivars. Incubation period was inherited independently of maturation period and pycnidial coverage, indicating that combinations of some of those characters may lead to more effective and durable resistance.     

Production of haploids in bread wheat, durum wheat and hexaploid triticale crossed with pearl millet

Pearl millet is an efficient alternative to maize as a pollen source for haploid production in bread wheat. To compare haploid production frequencies in other Triticeae species, the crossabilities of two genotypes each of bread wheat, durum wheat and hexaploid triticale with four pearl millet genotypes and a maize control were examined. Embryos were obtained from crosses of all three species with both pearl millet and maize. However, significant differences in crossability were found among the three species (10.5–79.8% seed development and 1.4–15.8% embryo formation), as well as among genotypes of durum wheat (7.2–23.7% and 2.1–6.4%) and hexaploid triticale (0.3–20.6% and 0.1–2.7%). Crossability of bread wheat with pearl millet was relatively high. Haploid plants were regenerated from crosses of all three species with pearl millet. As in the case of maize crosses, low crossabilities of durum wheat and hexaploid triticale with pearl millet can be attributed to the absence of D-genome chromosomes.     

水稻籼粳交衍生系产量相关性状的遗传效应与杂种优势

采用包括基因型与环境互作效应的加性—显性遗传模型(AD模型),对不同环境下水稻籼粳交衍生系产量相关性状的遗传效应与杂种优势进行研究。结果表明,播抽天数、每穗总粒数、每穗实粒数和千粒重性状以基因的加性主效应为主;结实率和株高性状以基因的显性主效应为主;基因型×环境互作效应明显影响产量相关性状表现,以显性×环境互作为主,其中播抽天数、单株谷重、千粒重和穗长的显性×环境互作效应尤为明显。杂种优势研究表明,由遗传主效应控制的杂种优势除单株有效穗数外,其余8个性状均表现正向群体平均优势;基因型×环境互作杂种优势分析表明,单株谷重、单株有效穗数、每穗实粒数、千粒重、株高和穗长6个性状杂种优势的稳定性较好。遗传效应分析结果表明,明恢413、97gk1037、明恢118和明恢417在多个性状上表现以遗传主效应为主,环境互作效应较弱,具有较好的环境稳定性,表明该4个籼粳交衍生品系在籼粳杂种优势利用中具有较高的利用价值。     

小麦面粉品质性状的遗传分析

组配了８个小麦亲本的双列杂交，以面粉品质性状进行了遗传研究，结果表明，所研究的８个品质性状的杂种优势均表现为显著或不显著的负向优势，优势的变异范围较大，杂种Ｆ１与亲本的关系密切，且倾低亲，８个性状中只有３个性状符合加性－显性模型，而形成时间断裂时间和弱化度存在上位性，吸水率为无显性，面粉蛋白质含量和稳定时间为部分显性，沉淀值为完全显性，评价值为超显性，品质性状的高值是受隐性基因控制的。