国内外蓖麻研究进展

蓖麻是世界十大油料作物之一,具有很高的经济价值,被人们视为很有开发潜力又可再生的“石油”资源．本文综述了国内外关于蓖麻杂种优势利用、蓖麻毒蛋白、组织培养技术及矮化性状等方面的研究进展,对蓖麻未来研究方向作了展望．     

玉米杂交种与亲本苗期根系蛋白差异表达谱分析

尽管杂种优势已经在生产上得到了广泛应用,但是对其形成机理的认识仍然非常有限．为了进一步探讨玉米杂种优势形成的分子机理,以玉米杂交种豫玉22及其亲本综3和87—1苗期根系为材料,采用蛋白质双向电泳和质谱鉴定技术进行了杂交种与亲本之间苗期根系差异蛋白表达谱研究．结果表明,发芽后8d的杂交种在根长、根尖数目、表面积和生物量等根系性状上均具有明显的杂种优势．双向电泳分析结果显示,在所检测到的1118个蛋白点中,有172个（15．38％）在杂交种与亲本的根系中发生了明显的表达变化,包括单亲沉默、杂种特异、杂种偏低亲、杂种偏高亲和中亲表达等5种差异表达类型,其中以单亲沉默所占比例最高．另外,鉴定出了56个差异表达蛋白点,发现其功能涉及转录和翻译、代谢、能量、信号转导、细胞结构、胁迫响应和转座元件等．因此,玉米杂交种与亲本在蛋白丰度上存在明显的差异,并且差异表达蛋白涉及到各个生长发育过程,可能与玉米根系杂种优势表现有关．     

Analysis of IGF2 mRNA expression and its methylation status between cattle yaks and their parents

Cattle yaks are an F1 hybrid between cattle and yaks and exhibit significant hybrid vigor. However, cattle yaks are sterile males. To study the epigenetic aspects of this reproductive isolation, IGF2 mRNA expression in cattle yaks and their parents and the patterns of the IGF2 differentially methylated regions (DMR) were examined in blood and testes. The results showed that IGF2 expression in cattle yaks’ testes was lower than in their parents (P < 0.01). The IGF2 DMR was highly methylated (above 90%) in blood and testes of cattle yaks, yaks and cattle, with the highest level in cattle yaks (P > 0.05). Our study showed that IGF2 plays an important role in bovine spermatogenesis and might be involved in cattle-yak male sterility. The methylation level of the IGF2 DMR was irrelevant to the lower expression of IGF2 in cattle yaks; other factors perhaps play roles in its expression.     

配合力分析在甜菜育种中的应用

通过对３个四倍体材料和４个二倍体材料配制测交组合１２个，进行配合力分析，优选出一般配合力最强的吉３３４和７４２／２两个亲本，配制的组合ＮＤ９０１６表现出很强的杂种优势。     

我国农作物两系法杂种优势育种和应用的进展

农作物育种的历史证实，有种新材料的发现和育种新方法的建立会推动农作物育种上升到更高的层次，由此促进农作物育种迅速发展，给农业生产带来新的局面。1997年9月6～8日在我国湖南长沙召开的首届“农作物两系法杂种优势利用国际学术讨论会”着重对我国在该领域内的最新研究成果进行了较系统的总结和交流。来自美国、日本、印度、孟加拉和越南等国的22位学者怀着崇敬的心情参加了这次具有历史意义的盛会。我国在农作物杂种优势利用方面正处在国际的前沿，不论在基础理论研究方面还是生产应用方面，我国所取得的研究成果都使外国学者感到欣…     

‘博采’(F_1)番茄杂种优势的早期生理预测研究

观测了新育成番茄组合‘博采’F1代及其亲本种子活力等生理指标,并以此作杂种优势的早期预测,同时研究了种子萌发过程中吸水量和呼吸速率的动态变化.结果表明:‘博采’F1代在室内的简化活力指数和活力指数等重要指标有明显超亲优势,而反交 F1代 (JD02×JD01) 杂种优势不明显,此结果与田间生产性能表现一致,故运用种子活力测定可作番茄杂种优势的早期预测.在采种和贮藏条件一致的条件下种子活力差异主要反映了基因型的差异,活力优势品种种子吸水较快、呼吸代谢强度较高、种胚生长旺盛.     

Relationship between differential gene expression patterns in functional leaves of maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) at milk filling stage and heterosis using cDNA-AFLP

To understand the molecular mechanism of maize heterosis ,differential gene expression patterns in the functional leaves of 35 maize hybrids relative to their parents involving 10 elite inbreds at milk filling stage were analyzed hy using cDNA-AFLP,the correlation analyses of various differential expression patterns with the performance and heterosis of main maize agronomic traits were evaluated.The main results were as follows:For uniparental specific expression ,significant positive correlations were detected with the performance of seed weight per ear and 100-seed weight at 0.01 and 0.05 probability levels respectively.For biparental specific expression ,significant negative correlations were detected with the performance of ear diameter and seed weight per ear at 0.01 probability level .For uniparental specific expression ,significant positive correlations were detected with the heterosis of ear diameter and seed weight per ear at 0.01 and 0.05 probability levls rspectively,For biparental specific expression .significant negtive correlation was detected with theheterosis of ear diameter at 0.05 probability level ,However,for F1-spectific expression,for fragments detected only in one parent and F1,and for fragments detected only in two parents or only in F1,no significant correlation was detected with the performance or heterosis of all agronomic traits surveyed.     

利用广亲和品种提高“三系”杂交稻优势的探讨

对02428、cpslo17、培矮64在三系杂交稻中的利用进行分析,结果表明,亲和力高低依次为cpslo17、培矮64、02428。cpslo17、培矮64含有对籼粳不育系的恢复基因,02428含有对粳稻不育系的恢复基因。三者与BT型不育系的产量配合力都较好,杂种有明显的优势。单株产量主要受单株有效穗数和每穗粒数的影响。     

水稻籼粳中间型RIL系主要农艺性状杂种优势分析

分析了遗传背景相同的籼粳中间型重组自交系（RIL）9个品系与5个籼、偏籼型光温敏核不育系杂交的F1主要农艺性状的杂种优势．结果表明：9个农艺性状均表现为正向超亲优势,以单株产量、穗实粒数、株高和穗总粒数表现的优势较强,有效穗数、结实率和千粒重表现的优势较弱;F1单株产量仅与父本穗长呈显著负相关,而与杂种有效穗数、穗实粒数、结实率和千粒重呈极显著和显著正相关;F1单株产量的超亲优势与父本单株产量、有效穗数、结实率均呈极显著负相关,与父本抽穗天数和千粒重却呈显著负相关,而与杂种的抽穗天数、有效穗数、穗实粒数、结实率和千粒重优势呈极显著正相关．亚种间杂交稻超高产的获得关键在于要协调好产量目标、亲本产量构成因素和其杂种优势三者的关系．