优质高产大花生新品种潍花6号的选育研究

潍花6号是潍坊市农科院以79266做母本，鲁花11号为父本进行有性杂交，系统选育而成。经1998—2001年山东、河北两省区试、生产试验及高产示范表明，该品种具有早熟、高产稳产、果大仁大、出仁率高、耐贮性好、口味佳等突出特点，2001年和2002年分别通过山东、河北两省农作物品种审定委员会审定，是一个适于中国北方花生产区栽培的优质高产大花生新品种。     

近15年国家自然科学基金稻、麦类作物遗传育种领域项目申请情况分析

国家自然科学基金是国家支持基础研究的主要渠道之一。本文以15年(1998—2012年)来国家自然科学基金中稻、麦类作物遗传育种面上类项目申请数据为依据,对稻、麦类作物遗传育种学研究的现状与趋势从研究领域和研究层次2个维度进行了深入分析。分析数据显示,15年来稻、麦类各类型项目申请量呈上升趋势,其中稻类项目的申请总量高于麦类项目。从研究领域来看,稻类研究项目申请量最多的是发育生物学,占稻类申请量的37.4%;其次是抗性,占27.6%。麦类作物研究主要集中在抗性研究领域上,占麦类申请量的38.1%;其次是发育及品质,分别占23.7%和21.5%。从研究层次来看,随着水稻基因组测序的完成,稻类研究领先于小麦研究。稻类研究项目申请量最多的基因克隆与功能分析,占稻类申请量的41.6%;其次是分子标记与基因定位,占28.8%。麦类研究申请量最多的是分子标记与基因定位,占麦类申请量的36.5%;其次是基因克隆与功能分析,占28.2%。综合国内外研究现状,建议今后在继续加强对围绕高产、优质、高效、抗逆等研究持续资助的基础上,积极支持将基因组学、生物技术和生物信息学与传统作物学相结合的基础研究。     

Trial heterogeneity and variance models in the genetic evaluation of potato tuber yield

Genetic evaluation aims to identify genotypes with high empirical breeding values (EBVs) for selection as parents. In this study, 2157 potato genotypes were evaluated for tuber yield using 8 years of early‐stage trial data collected from a potato breeding programme. Using linear mixed models, spatial parameters to target greater control of localised spatial heterogeneity within trials were estimated and variance models to account for across‐trial genetic heterogeneity were tested. When spatial components improved model fit, correlations of errors were mostly small and negative for marketable tuber yield (MTY) and total tuber yield (TTY), suggesting the presence of interplot competition in some years. For the analysis of multi‐environment trials, a variance model with a simple correlation structure (with heterogeneous variances) was the most favourable variance structure fitted for TTY and PTY (per cent marketable yield). There was very little difference in model fit when comparing a factor analytic structure of order 2 (FA2) with either FA1 or simple correlation structures for MTY, indicating that simple variance models may be preferable for early‐stage genetic evaluation of potato yield.     

Identification of marker alleles linked to fire blight resistance QTLs in apple genotypes

Molecular marker analysis can be an effective tool when searching for new fire blight resistance donors. It can speed up the breeding process as well, even though many of the available markers linked to fire blight resistance QTLs have not yet been tested by screening a large number of cultivars. The aim of this study was to search for alternate sources of the three major QTLs of fire blight resistance; FBF7, FB_MR5 and FB_E, as well as to test the efficiency of some markers linked to minor QTLs. Altogether, nine primer pairs were used on 77 genotypes including new Hungarian cultivars and old apple cultivars from the Carpathian basin. Several marker alleles of FB resistance QTLs have been detected in the screened genotypes, most importantly the alleles coupling with FB_MR5 in the old cultivars ‘Kéresi muskotály’, ‘Szabadkai szercsika’ and ‘Batul’. We propose these cultivars as the first available resistance donors of FB_MR5 instead of the crabapple Malus × robusta 5. The results also bring new information regarding the resistance alleles of new Hungarian cultivars and selections.     

Implications of the number of years assessment on recommendation of common bean cultivars

In the common bean crop in Brazil, the requirement of the value for cultivation and use trials is that these experiments must be conducted over two years in three locations per region. Information in regard to the necessary number of years to ensure precision in cultivar recommendation and the influence of evaluated years in the estimation of the GE interaction are still scarce. Using grain yield of five check varieties assessed over 11 years in three sowing seasons per year, the aims of this study are as follows: to measure the relative contribution of the GE interaction, evaluating the implication of the number of years in the estimates of the GE interaction, and infer how many years are needed to ensure precision in cultivar recommendation. For instances, analysis of variance was carried out involving all environments and also combinations of years. The results showed that the GE interaction was greater than all other cross‐effects involving lines. The use of at least two years allows good coincidence in cultivar recommendation compared to the whole period. Increasing the evaluation time is a good strategy, especially when it is difficult to grow three different sowing seasons.     

甜（辣）椒耐低温弱光品种筛选方法初探

通过在不同的低温弱光条件下，对８个代表性品种的冷害发生发展规律的研究，初步确定：１５℃／５℃（昼／夜）、光照强度４０００ｌｘ、光照时间８ｈ、处理１５天，是耐低温弱光品种的适宜选择压力。在此条件下，耐低温品种不出现伤害症状和落叶现象，叶片生长速度快；不耐低温品种生长缓慢，落叶严重，且生长点呈黑褐色，以至干枯。品种间差异显著。同时，耐低温品种叶片叶绿素含量增加，而不耐低温品种叶绿素含量下降。这一结果为进一步完善耐低温弱光品种的鉴定方法提供可靠的依据     

大白菜抗根肿病基因位点CRa和CRb的分子标记鉴定

利用大白菜抗根肿病基因CRa和CRb分子标记(SC2930和KBr H129J18R)引物组,对78份大白菜材料进行抗根肿病分子标记鉴定。结果表明,在这78份材料中,有34份材料含有SC2930-T(CRa抗病标记)标记,其中杂合抗病位点材料17份,纯合抗病位点材料17份。有37份材料含有KBr H129J18R抗病标记,其中纯合抗病位点材料15份,杂合抗病位点材料22份。有20份材料不含有CRa和CRb所对应的抗病标记,23份材料含有2个抗病标记。该研究初步明确了78份参试大白菜材料所含抗根肿病基因CRa和CRb类型,为大白菜抗根肿病育种提供材料选择依据。     

Fusarium wilt of chickpea: physiological specialization, genetics of resistance and resistance gene tagging

Chickpea wilt caused by Fusarium oxysporum f. sp. ciceris is one of the major yield limiting factors in chickpea. The disease causes 10–90% yield losses annually in chickpea. Eight physiological races of the pathogen (0, 1A, 1B/C, 2, 3, 4, 5 and 6) are reported so far whereas additional races are suspected from India. The distribution pattern of these races in different parts of the world indicates regional specificity for their occurrence leading to the perception that F. oxysporum f. sp. ciceris evolved independently in different regions. Pathogen isolates also exhibit differences in disease symptoms. Races 0 and 1B/C cause yellowing syndrome whereas 1A, 2, 3, 4, 5 and 6 lead to wilting syndrome. Genetics of resistance to two races (1B/C and 6) is yet to be determined, however, for other races resistance is governed either by monogenes or oligogenes. The individual genes of oligogenic resistance mechanism delay onset of disease symptoms, a phenomenon called as late wilting. Slow wilting, i.e., slow development of disease after onset of disease symptoms also occurs in reaction to pathogen; however, its genetics are not known. Mapping of wilt resistance genes in chickpea is difficult because of minimal polymorphism; however, it has been facilitated to great extent by the development of sequence tagged microsatellite site (STMS) markers that have revealed significant interspecific and intraspecific polymorphism. Markers linked to six genes governing resistance to six races (0, 1A, 2, 3, 4 and 5) of the pathogen have been identified and their position on chickpea linkage maps elucidated. These genes lie in two separate clusters on two different chickpea linkage groups. While the gene for resistance to race 0 is situated on LG 5 of Winter et al. (Theoretical and Applied Genetics 101:1155–1163, 2000) those governing resistance to races 1A, 2, 3, 4 and 5 spanned a region of 8.2 cM on LG 2. The cluster of five resistance genes was further subdivided into two sub clusters of 2.8 cM and 2.0 cM, respectively. Map-based cloning can be used to isolate the six genes mapped so far; however, the region containing these genes needs additional markers to facilitate their isolation. Cloning of wilt resistance genes is desirable to study their evolution, mechanisms of resistance and their exploitation in wilt resistance breeding and wilt management.     

Incidence and molecular markers of 2n pollen in Populus tomentosa Carr.

Microscopic examination, amplified fragment length polymorphism (AFLP) and SCAR (sequence-characterized amplified region) molecular markers were employed to determine the incidence of 2n pollen (unreduced pollen) in Chinese white poplar (Populus tomentosa Carr.) and to identify related molecular markers. The presence of a parallel and tripolar spindle at metaphase II and the absence of cytokinesis at telophase II were found to be determining factors in 2n pollen formation. A group of 298 clones that originated from their indigenous areas were investigated for the production of 2n pollen based on pollen size differences, both within a clone and between n and 2n pollen. Pollen grains were collected from 224 of the clones, six of which were subsequently determined to produce only normal pollen; the remainder produced 2n pollen at different frequencies (0.6–21.9%). The frequency at which 2n pollen was produced was significantly and highly significantly different among and within indigenous populations, respectively. Clones produced by the six normal and twenty-two 2n pollen clones were selected for AFLP analysis. Following an initial screening with 55 primer combinations, the E50-M38 (CAT/ACT) primer was identified: it generated a PCR fragment (246 bp) from the normal clones, but not from the 2n pollen producers. In addition, the E31-M50 (AAA/CAT)-amplified DNA fragment (204 bp) was present in 2n pollen producers, and absent in normal clones. These two discriminating AFLP markers were developed into easily detectable SCAR (sequence characterized amplified region) markers which can be used in combination with previously developed AFLP markers to distinguish between normal and 2n pollen clones.     

The long and winding road leading to the successful introgression of downy mildew resistance into onion

Downy mildew resistance originating from Allium roylei Stearn provides a complete resistance to onions and is based on one, dominant gene. Since A. roylei can successfully be hybridized with onion (A. cepa L.), a breeding scheme aimed at the introgression of this gene was initiated ca. 20 years ago. Several setbacks in this programme were encountered, firstly the identified molecular marker linked to the downy mildew resistance locus became increasingly difficult to use and finally lost its discriminating power and secondly the final step, making homozygous introgression lines (ILs), turned out to be more difficult then was hoped. GISH analysis showed that the chromosomal region harbouring the resistance locus was the only remaining piece of A. roylei in the nuclear background of onion and it also confirmed that this region was located on the distal end of chromosome 3. It was hypothesized that some factor present in the remaining A. roylei region was lethal when homozygously present in an onion genetic background. The identification of an individual with a smaller and more distally located introgression fragment and homozygous ILs in its progeny validated this hypothesis. With the help of these nearly isogenic lines four AFLP^® markers closely linked to the resistance gene were identified, which can be used for marker-aided selection. The introduction of downy mildew resistance caused by Peronospora destructor into onion is a significant step forward in the development of environmentally-friendly onion cultivars.