玉米DH系产量性状配合力相关分析

以DH系为亲本组配杂交组合为对象,采用数量遗传学方法研究DH系产量相关性状的遗传变异规律。结果表明,诱导DH系的基础材料决定其诱导后代的类型,DH系的穗长、穗粗、穗行数、行粒数、百粒重等产量相关性状符合基因加性效应遗传规律。利用DH育种技术可以快速改良自交系的一般配合力(GCA),组配优良的杂交组合。     

Development of high-oil maize haploid inducer with a novel phenotyping strategy

Doubled haploid(DH) technology is important in modern maize breeding. Haploid inducers determine the efficiency of both haploid induction and identification. It has taken decades to improve the efficiency,haploid induction rate(HIR), from the ~2% of the ancestor haploid inducer, stock6, to the ~10% of modern haploid inducers. Improvement of kernel oil content(KOC) would further enhance haploid identification efficiency. Using molecular marker-assisted selection, in combine with the number of haploids per ear as phenotypic criterion, we developed a new high-oil haploid inducer line, CHOI4, with a mean HIR of 15.8%and mean KOC of 11%. High KOC of CHOI4 can achieve a mean accuracy greater than 90% in identification of haploids of different backgrounds, with reduced false discovery rates and false negative rates in comparison with the previous high-oil haploid inducer line, CHOI3. Comparison of phenotypic selection strategies suggested that the number of haploids per ear can be used as a phenotyping criterion during haploid inducer line development. CHOI4 could further increase the efficiency of large-scale DH breeding programs with lower cost.     

玉米单倍体雄穗自然加倍性轮选遗传修复与高加倍率材料的创制

利用DH技术对先玉335进行连续轮回选择,发现单倍体雄穗自然加倍能力具有极显著的累加遗传效应,这种遗传效应可以获得成倍提高。证明玉米自身遗传系统具有单倍体雄穗自然加倍遗传恢复(修复)能力。用两轮选择所获的DH2系再次杂交组群,再经杂交诱导获得单倍体植株平均雄花散粉率高达85.15%,自交结实率高达66.18%,是基础群体先玉335直接诱导单倍体株的6.99倍和9.86倍。获得的DH3系因经两轮全基因组配子体选择,最大限度地淘汰了有害、劣性基因,聚合了较多优良基因,农艺性状好,植株长势强,可直接应用于资源扩增和品种选育。单倍体雄穗自然加倍性的轮选遗传修复能力的发现与高自然加倍率材料的创制具有极其重要的应用价值,可与玉米双轮回选择育种模式相结合,构建基于自然加倍为主体的单倍体双轮回育种技术体系。     

大麦加倍单倍体(DH群体)的建立及其在遗传育种中的应用

大麦加倍单倍体 (DH群体 )建立的方法很多 ,目前在大麦遗传育种中运用较多的主要有球茎大麦法、花药培养法和小孢子培养法等三种。大麦DH群体不仅为遗传学、形态发生学和分子生物学等基础研究提供了丰富的背景和遗传稳定的材料 ,而且对于单倍体的育种实践也有重要意义。本文简要综述大麦DH群体的建立方法及其在遗传育种中的应用 ,以期为大麦遗传育种研究提供参考     

源于大麦F1小孢子氮胁迫培养自交一代的耐低氮性评价

为了探索快速改良大麦耐低氮性状的育种方法,以2份耐低氮亲本配制（正反交）杂交组合,游离其F₁代小孢子进行氮胁迫培养,获得85个加倍单倍体（Double haploid,DH）系。取其种子播种于正常供氮和降氮的土壤中,以亲本作对照,观察群体的形态特征表现,以此对耐低氮性进行初步的评价。同时,对耐低氮性明显超亲的基因重组体进行氮代谢相关的生理生化指标分析,以探讨其与有关农艺性状的相关关系。结果表明,（1）通过氮胁迫相关的形态特征鉴定,正反交DH系低氮胁迫响应的相对值优于亲本;（2）筛选到10份明显优于双亲的DH系,对其进行相关酶活力测定,发现在低氮胁迫下,谷氨酰胺合成酶（GS）活力相对值与成熟期单株产量存在极显著正相关性,可以初步作为成熟期氮素营养检测的生化指标。依据研究结果可以认为,运用杂交结合F₁小孢子氮胁迫培养方法,能够产生耐低氮性优于双亲的DH系。     

玉米杂交诱导单倍生殖(单倍体)选育自交系技术规范(暂行版)

汇总国内外单倍体育种研究理论与经验,经美国著名单倍体育种家张铭堂指导,组装集成出本规范,供试用参考。本规范制定了杂交诱导单倍生殖方法选育自交系的基本操作程序,将单倍体杂交诱导、子粒鉴选、植株确认、自然与人工加倍及双单倍体获得5个环节作出技术规定。在每个环节都还有技术关键(特别是人工加倍等多属商业机密范畴)在试用与待熟化。经多年实践验证,按此规范程序,只需2～3个生育世代即可批量选育出遗传高度纯合自交系。     

选育高含油量双低油菜品种的理论与实践

含油量作为油菜生产最终目标性状产油量的组成因素,与油菜生产效益的提高息息相关。在目前我国 油菜产量水平已得到相当程度提高的前提下,培育高含油量油菜品种是进一步发展油菜产业的必由之路。根据油 菜含油量的遗传特点,结合培育高含油量杂交油菜品种中油杂8号和中油杂11的体会,提出了除了利用黄籽以 外,培育大粒和适宜植株形态性状的品种也是提高油菜含油量的重要途径。初步构建了高含油量油菜品种的形态 组成,并基于近年来参加和通过国家区域试验的冬油菜品种含油量变化情况,展望了我国高含油量油菜育种的发 展前景。     

Association of growth dynamics, yield components and seed quality in long-term trials covering rapeseed cultivation history at high latitudes

Brassica oilseed yield trend has declined in Finland by over 20% during the last 15 years. Improved genetic yield potential of turnip rape (B. rapa L.) and oilseed rape (B. napus L.) can be better realised with increased understanding of yield determining processes under northernmost growing conditions. This study aimed at (1) determining the genetic improvements in seed yield, yield components, quality traits and duration of the main growth phases and (2) comparing all these traits in turnip rape and oilseed rape. This work is based on the dataset from long-term Official Variety Trials (1976–2006), covering the entire historically relevant period of rapeseed cultivation in Finland. The results indicated that number of seeds per square metre dominated production of high yields, while single seed weight was not correlated with yield. Over the years, seed yields were produced with very different combinations of seed numbers and weights, differing markedly between the two crops. While high seed numbers were required for production of superior seed yields, single seed weights were not particularly high. Environmental variation markedly affected seed yield, seed number per square metre and duration of flowering compared with its effect on single seed weight. Duration of flowering was, however, negatively associated with seed number. Even though seed weight was largely determined by genotype, no marked plant breeding improvements were identified, contrary to those in number of seeds per square metre, seed yield, oil content and oil yield. For oilseed rape the increase in seed yield (41%) was far higher than for turnip rape (19%) without being associated with a longer seed-filling phase and later ripening, but rather the contrary.     

玉米单倍体自然加倍若干问题探讨

玉米单倍体加倍是DH育种中的关键技术环节之一,玉米单倍体雄穗自然加倍能力较低,限制了DH育种技术在商业育种中的大规模推广,对玉米雄穗自然加倍遗传特性的研究将有助于DH技术在育种中的进一步应用。本研究通过对多个不同遗传背景的单倍体雄穗自然加倍能力进行严格统计和差异比较,结果表明,单倍体雄穗育性恢复主要受核基因的控制,不受细胞质基因的调控。诱导率对单倍体雄穗自然加倍能力没有显著影响,自交系来源的DH1经过诱导后的单倍体由于基因型没有变化,其自然加倍能力与自交系相比没有显著提高。     

玉米杂交诱导单倍生殖育种工具材料——单倍体诱导系

玉米育种的关键在于自交系的选拔。优良自交系选育的质量和速度决定了组配杂交种的水平和表现。传统的自交系选育方法所需周期长、规模大、费时费力,已不能适应现代市场对于新品种的需求。目前,最好的方法是双单倍体育种方法,此方法通过单倍体诱导系可以诱导产生10%左右的母本单倍体种子,经过加倍处理,即可获得100%纯合的自交系。杂交诱导单倍体育种方法的根基是诱导系的创制与诱导率提升。     

甘蓝型油菜减氮增效潜力评价及种质资源筛选

为培育具有高潜力的减肥增效油菜品种,以不同甘蓝型油菜种质资源为材料,通过两年三点的田间肥效 试验,研究了它们对氮肥的响应特征及节氮增产潜力。以产量平均值为分界线将供试材料划分为4种类型：低氮高 效型、双高效型、双低效型和高氮高效型。在高氮条件下,双高效型和高氮高效型材料具有16.96%~36.50%的节氮 潜力和21.57%~49.59%的增产潜力;在低氮胁迫下,低氮高效型具有12.23%和10.88%的节氮及增产潜力。同时筛 选出低氮高效型材料中双9号、SV-pyriter,双高效型材料D4-15、中双11号、DH16、华双3号,双低效型材料D2-1、 华双5号、加99H99-15HR、湘农油3号、DH17,以及高氮高效型材料84001。研究表明,甘蓝型油菜减氮增产增效的 潜力较大,但存在较大的基因型差异。因此,选育双高效型和高氮高效型材料可能是今后油菜育种的重点。     

玉米DH系遗传参数分析和育种效果

利用PH4CV×A6 F1进行单倍体育种,育成336份DH系为父本、以PH6WC为母本组配336个杂交组合,通过2年鉴定淘汰后综合性状较好的14个组合及先玉335(PH6WC×PH4CV)、通育99(PH6WC×A6)进行3次重复鉴定试验,就10个性状加显性效应进行方差、遗传系数和聚类分析。结果表明,株高、穗位高、子粒水分、百粒重和容重存在超高亲、超低亲遗传,粒穗比存在超高亲遗传,穗粒重无超高亲遗传。各性状对穗粒重通径系数影响,正向作用为百粒重穗行数穗长容重株高穗位高,负向作用为子粒水分粒穗比秃尖长(绝对值)。14个DH系可划分为3个群,PH4CV和A6的卡方距离为3.45,D752与A6卡方距离为1.96。单倍体育种实践,D752穗粒重加显性效应达到PH4CV水平,同时兼顾了低株高、低穗位等多数优良性状,改良效率为0.30%(1/336)。     

Bacillus megaterium A6 suppresses Sclerotinia sclerotiorum on oilseed rape in the field and promotes oilseed rape growth

Sclerotinia sclerotiorum causes serious yield losses in oilseed rape and other crops worldwide. Field trials were conducted at two locations to evaluate two formulations of oilseed rape seed containing the plant-growth promoting bacterium Bacillus megaterium A6 for suppression of this pathogen. Treatments containing strain A6 in pellet and in wrap formulations resulted in oilseed rape seed yields that were similar to the chemical control and significantly greater than the untreated seed control at both locations. Treatments containing A6 in pellet and wrap formulations also resulted in an incidence of disease caused by S. sclerotiorum that was similar to the chemical control. Both of these treatments significantly decreased disease incidence relative to the untreated seed control and to the respective formulated seed controls (that did not contain strain A6) at both locations. Strain A6 applied to oilseed rape seed in these two formulations promoted growth in greenhouse pot studies conducted with autoclaved soil. In two experiments, these treatments resulted in significant increases in mean shoot dry weight per pot and mean % total N per plant relative to their respective controls containing formulated oilseed rape seed without strain A6 and to the untreated seed control. Both formulations provided stable B. megaterium A6 (≥10⁶ CFU) and seed germination (>85%) over a six month period at room temperature. Experiments reported here indicate the commercial potential of these formulations of B. megaterium A6 for suppression of S. sclerotiorum on oilseed rape.     

Responses of Seed Yield and Quality to Nitrogen Application Levels in Two Oilseed Rape (Brassica napus L.) Varieties Differing in Nitrogen Efficiency

Abstract

The relationship between nitrogen efficiency (NE), defined as seed yield per unit nitrogen (N) application, and seed quality was examined in two oilseed rape (Brassica napus L.) varieties at 5 N application levels, 0.6, 3, 6, 12, 15 mmol L?¹, N₁, N₂, N₃, N₄ and N₅, respectively. Seed yield, oil yield and protein content were increased with the increase in N application level, but NE and oil content were decreased, and the fatty acid composition in seed was hardly changed. Analysis of seven fatty acids revealed aslight decrease in the contents of erucic acid and arachidonic acid with the increase in N application level, but no obvious change in the contents of palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. Compared with the low NE variety H29, the seed yield and contents of erucic acid and arachidonic acid in the high NE variety bin270 were more markedly increased with the increase in N application level, and the oil content was hardly changed. The seed yield, oilcontent and oil yield were higher in the high NE variety than in the low NE variety at all 5 N application levels. There were no significant differences in protein, palmitic acid, stearic acid and oleic acid contents between the varieties at any of the 5 N application levels, but there were slight differences in the linoleic acid and linolenic acid contents between the two varieties. In brief, N application improved oil yield more greatly in the high NE variety than in the low NE variety, but hardly affected the fatty acid composition. Therefore, the seed quality and oil content of oilseed rape may not be decreased by breeding of a high NE variety with a high N absorption efficiency and high N use efficiency.     

不同种质茶籽脂质代谢特征分析

叶籽两用茶树种质的研发利用对于茶产业结构调整、茶园综合效益提升具有特殊意义,因此深入研究现有茶树种质与茶籽相关性状特征,可为叶籽两用茶树的遗传育种提供基础信息。从福建、云南和湖南采集了31份同年结实茶籽,对种仁的含油率和脂肪酸组成特征进行测定。结果表明,不同茶树茶籽含油率存在2倍以上的差异;从茶籽油脂中检测到10种脂肪酸组分,包括棕榈酸、棕榈油酸、顺-11-十六碳烯酸、硬脂酸、油酸、顺-11-十八碳烯酸、亚油酸、亚麻酸、二十烷酸和二十烯酸。油酸是茶籽中的主要脂肪酸,占脂肪酸总量的42.1%~59.2%;其次为亚油酸,占脂肪酸总量的18.9%~32.8%;饱和脂肪酸含量占15.9%~20.8%,以棕榈酸为主。进一步分析各种质的脂肪酸组成特征,发现茶籽中的FAD2和FAD3活力在种质间存在较大差异。在此基础上,探讨了如何利用这些发现来选择育种,以进一步改善茶籽的油脂性状。     

Persistence of an oilseed rape transgene in the environment

Transgenic bromoxynil (BX)-resistant spring oilseed rape (Brassica napus L.) was grown commercially in Canada only for two crop seasons – 2000 and 2001. We investigated the persistence of suspected BX-resistant oilseed rape volunteers in a 64-ha wheat field in Saskatchewan, Canada in 2007, 7 years after the BX-resistant cultivar BX Armor was grown. A small oilseed rape volunteer population, estimated at less than 100 plants, was observed in three main areas or patches in the field. These patches were located in low-lying areas that were too wet to plant or spray with herbicides in 2007. Viable seed was collected from 35 mature volunteers and F₁ progeny screened with BX at 280 g ai/ha in the greenhouse. Progeny of all of the volunteers were visually rated as BX-resistant; the presence of the Oxy 235 transgene in leaf tissue of progeny of all volunteers was confirmed by PCR analysis. This study has documented the longest persistence of oilseed rape volunteers in Canada. Volunteers were not observed in 2008 or 2009, because of drought conditions in spring of both years. Results support the findings from previous studies that persistence of volunteer oilseed rape populations in western Canada is generally ephemeral or transitory in the absence of seed bank immigration. However, this study shows that oilseed rape transgenes can persist in the environment for a number of years even after all cultivars with the conferred trait are removed from the market.     

越南油茶40年生实生林优株筛选与遗传多样性分析

为了筛选越南油茶实生老林优株和探讨实生变异的遗传多样性,在海南省保梅岭生态保护区以40年生油茶老林32个丰产单株为试验材料,开展了主要农艺性状、经济性状和品质性状的田间调查和实验室检测。结果表明：从32个丰产单株中筛选出果实丰产性良好或果实、种子含油率较高的优株共20株,其中金波5号和23号果实丰产、果实和种子含油率较高;32个单株茶籽油理化性质和脂肪酸含量基本上都达到了《油茶籽油》（GB/T11765-2018）的要求;依据农艺和经济性状、茶籽油理化性质和茶籽油脂肪酸组成等差异分别作聚类分析,可以分别归属成6类（r ²=0.932）、10类（r ²=0.864）和7类（r ²=0.937）,3项聚类分析结果都能区分出丰度较高和较低的基因型种类,20个优株分别归属到全部6类、10类中的7类和全部6类中,说明越南油茶实生变异存在丰富的遗传多样性、不同种类基因型存在丰度差异,不同优株分属不同基因型种类。可见,越南油茶的育种目标应以丰产性和稳产性为主,金波5号和23号是有希望上升为品种的优株;越南油茶具备丰富的遗传多样性,且不乏有特色的稀有种质。     

农大高诱1号对玉米不同种质类群诱导单倍体的效果初探

利用农大高诱1号对玉米不同种质类群S1代进行单倍体诱导,结果表明：不同种质类群平均单倍体诱导率为3．2％,不同类群间存在显著差异,对Lancaster群授粉所产生的群单倍体诱导率最高为4．6％,比Reid、唐四平头和旅大红骨类群诱导率高,达到5％显著水平,对热导地方种质群最低为1．8％,达到1％极显著水平。因此,最优诱导单倍体类群为Lancaster群。对5个基础种质群进行诱导,都表现为单倍体雌稳自然育性恢复较高,果穗结实株率平均达到92．9％。雄稳自然育性恢复极低,不同基因型材料诱导产生出的单倍体雄穗育性存在很大差异,5个基础种质群单倍体平均散粉率7．4％,旅大红骨和Lancaster群中诱导出的单倍体的散粉株率最高。获得的13个DH系在株高、散粉期和果穗特性等农艺性状表现一致,并且试配参加田间试验。     

Breeding and biotechnological efforts in Jatropha curcas L. for sustainable yields

Jatropha is a non-edible, important bioenergy plant, which can grow in marginalized land. The seeds possess about 36% oil and this would be converted into biodiesel or biojet-fuel. Jatropha provides an option for sustainable feed and fuel production due to its inherent qualities including hardy nature, drought tolerance and surviving with limited amount of water, tolerance to unfavorable conditions and excessive moisture. However, heterozygosity, low productivity and poor understanding of its genome are the major impediments to elite line development. Further, classical breeding and advanced technological investments remain limited owing to long juvenile phase and breeding cycles. Scientific technologies that lead to identification of elite genotypes and development of high yielding elite Jatropha lines and effective methods of detoxification of seeds needs immediate priority. Efficient tissue culture system, doubled haploids (DH) and genomic tools are increasingly made available to improve the seed yield and its oil quantity through the development of geminivirus disease resistant lines. The application of advanced, sequencing technologies has presented a repertoire of genomic information for this important yet orphan crop. In the present investigation, we highlight the achievements made in Jatropha towards development of high yielding, virus resistant elite lines and hybrids with yield potential ranging from 3 to 5 tons per hectare in a year, which is a first ever report in the world. We also developed potential biotechnological tools such as genetic transformation, genome editing and next generation genomics tools including linkage maps and QTLs for accelerating breeding efforts through marker assisted selection. Because of our concerted and continuous efforts during the past 15 years, we have overcome all the obstacles and developed high yielding, disease resistant hybrids/lines, advanced cultivation technologies with thorough knowledge on Agronomy of the Jatropha crop. The Jatropha cultivation technology developed for the first time in the world, could open up new avenues for higher yield productivity of commercial viability.