【作者】 赵世勇；

【导师】 荣廷昭；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2003， 博士

【摘要】 玉米是四川主要的粮食作物，又是重要的饲料作物及适于深加工获得多种产品的经济作物。全省常年种植面积125万公顷，总产620万吨。近二十年来，四川玉米生产有了长足的发展，总产连续上了三个台阶。但作为一个养猪大省和酿造大省，四川玉米供需矛盾依然十分突出，每年要从省外调进大量的玉米。怎样在现有育种基础上，进一步提高我省玉米育种水平，为二十一世纪四川玉米生产持续稳定增长提供保障是我省玉米育种工作者和农业科技管理工作者十分关注的问题。据此，本研究的目的是对曾经为四川玉米生产作出巨大贡献的二十世纪最后二十年的玉米育种进行总结，科学分析取得成就的原因，进而探讨二十一世纪前十年四川玉米育种的主要目标和主攻方向。 本文分析了1981-2000年四川省杂交玉米区域试验参试杂交种的农艺性状、品质性状及抗病性的变化；以1981—2000年四川省杂交玉米区域试验平丘组和山区组每年前两名组合的亲本共30份为材料进行了主要自交系的完全双列杂交试验，分析了参试自交系的一般配合力和特殊配合力；在上述30个自交系中去掉齐205、286-4、南21-3和156四个自交系，增加了48-2A、黄早四、丹340、18-599红共30个四川主要玉米自交系进行了SSR分析。得到如下主要研究结果： 1、二十年里，四川杂交玉米区域试验产量逐年增加，尤以“九五”在“八五”基础上增幅最大，山区组增幅大于平丘组。平丘组的产量提高主要依赖于穗行数的增加；山区组产量的提高是千粒重、穗行数和行粒数三者共同的结果，其中千粒重的增加起主要作用。 2、二十世纪90年代初育成的玉米品种小斑病的抗源相对较多，而对大斑病、丝黑穗病表现为抗的材料较少；随着时间的推移到90年代中后期，大斑病和丝黑穗病的抗源有明显的增多，绝大多数育成品种对三种主要病害都有较好的抗性。从整体上讲，四川玉米抗病育种水平在不断提高。 3、二十年里，四川育成玉米品种的籽粒品质性状没有较大的变化。其中，蛋白质、淀粉含量随杂交育种年代的推移无显著变化；只有籽粒中的脂肪含量随育种年代的推移略有提高。 4、四川80年代育成自交系与90年代育成自交系相比，生育期、穗长、行粒数变化不大，株高、穗行数略有下降，千粒重却表现出增加趋势。双列杂交分析结果表明，一般配合力和特殊配合力在供试材料之间均达极显著水平，30个自交系间存在配合力的多样性，且多数自交系之间的一般配合力差异达显著或极显著水平。杂交种的优势表现有些是一般配合力在起主要作用，如川单9号 (48一2 x 5003)、川单15(48屯x 256)等;有些是特殊配合力在起主要作用，如绵单l号(81565x南21一3)、成单22(238 x 273)等;还有些是一般配合力和特殊配合力同时在起作用，如成单19(成687 x 7327)、川单21(R08 x 528)、雅玉2号(7922 x 537)、成单14(32 x 200B)等。 5、利用85对SSR引物对30个玉米自交系进行同源位点扩增，其中47对的扩增产物在4.5%的聚丙烯酞胺凝胶上具有多态性，带型稳定。这47对SSR引物分布于玉米全部10条染色体上，在30个自交系间共检测出 185个等位基因变异，每对引物检测到2一7个等位基因，平均为3.9。每个位点的多态性信息量 (plc)变化于0.够(PhilZI)一心.79(phiols)之间，平均为0.57。SSR标记的聚类结果与杂交种田间实际表现及系谱追踪结果吻合性较好，表明应用SSR对自交系进行聚类分析合理，可以指导杂种优势群的划分和杂优模式的选配。 6、二十年里，四川玉米自育种的产量水平有明显的提高，玉米生产产量的增加趋势与区试产量增加趋势基本一致，育成品种数量逐年明显增加，自育品种的亲本组成中自育自交系的数量有较大提高，全省自育种的推广应用面积占播种面积的比率由“七五”的18，14%上升到“九五”的7既左右，单产由“七五”的3687公斤/公顷上升到“九五”的4806公斤/公顷，四川已彻底改变了杂交玉米主要靠外引品种的局面。 7、在上述研究的基础上，本文对四川省近二十年来玉米育种取得的长足进步、玉米生产水平大幅提高的原因进行了较为详尽的分析与探讨，认为:(1)玉来自交系和杂交种选育与群体遗传组成研究和群体改良同步进行的育种新方法的提出与实施，姊妹系及改良单交种的研究与应用，雄性不育系的创制、研究及利用等一系列玉米育种方法的创新是我省玉米育种取得进步的关键;(2)热带种质的研究利用及新杂优模式的建立，四川省地方种质资源的研究与利用等因素是我省玉米育种取得进步的核心;(3)“四川省玉米育种协作攻关小组”的组建与良好运行及政府财政的大量投入是我省玉米育种取得进步的保证。 8、通过四川玉米需求分析和四川玉米改良潜力分析，提出二十一世纪前十年四川玉米育种的主要目标为:区域产量g000kg/ha，容重7109/L以上，出籽率87%以上，籽粒较深。平丘玉米要求粒型较紧凑，密度52500株/ha，穗行数16、行粒数35、千粒重3109;山区组玉米密度45000株/ha、每穗16行，每行40粒，千粒重3159;要求育成玉米新品种在保持对大、小斑病、丝黑穗病和矮花叶病的抗性下，还应更多还原

【Abstract】 Maize is a major grain crop in Sichuan Province and also an important feed crop and a cash crop suitable for the deep processing into various products. Its sown area is 1.25 million hectares for an average year in the whole province, with a total production of 6.2 million tons. Over last 20 years, the maize production in Sichuan has developed substantially and its total production has got three consecutive leaps. However, as a big province in pig production and brewery, Sichuan still has a very sharp contradiction between the demand and the supply of the maize and imports a large quantity of maize from other provinces every year. It is an issue of very great concern for maize breeders and agro-technical management personnel in Sichuan Province how to further improve maize breeding level based on the existing breeding capability in order to ensure a sustainable and steady increase of maize production in Sichuan in the 21st century. The purpose of this research is to summarize the work of maize breeding which once made a great contribution to maize production in Sichuan Province, to analyze in a scientific way the causes of its achievements and subsequently to discuss the countermeasures and main direction of attack for maize development in Sichuan Province in the 21st century.Data in hybrid maize regional trails in Sichuan Province from 1981 to 2000, and analyzes the agronomic traits, quality characters and changes of disease resistance of hybrid maize varieties included in the regional trails over last 20 years are collected. 30 inbreds, which are obtained from a combination of each year’s first two in mountain group and plain and hilly group of hybrid maize regional trails in Sichuan Province from 1981 to 2000, are used as materials to conduct a complete diallel cross trial of main inbred lines. Based on 30 inbred lines mentioned above, by adding 48-2A, HUANG ZAO SI, DAN 340 and 18-599- Red and removing four inbred lines QI 205, 286-4, NAN21-3 and 156, the SSR analysis has been conducted on 30 main maize inbred lines in Sichuan Province. The main results are as follows:1. During last 20 years, the production of hybrid maize in regional trails inSichuan Province have been increased year by year, with the largest margin during the Ninth Five-Year Period over the Eighth Five-Year Period, and mountain group greater than plain and hilly group. The increased production in plain and hilly group mainly results from the increased number of ear-lines and the increased production in mountain group comes from joint efforts of the weight of 1000 kernel, the number of ear-lines and the number of line-kernel, with the weight of 1000 kernels playing a major role.2. Over last 20 years, the maize hybrids bred in the early 1990s have relatively more resistance germplasms on bipolaris Maydis than on northern corn leaf blight and maize head smut Those bred in the middle and late 1990s have more resistance germplasms on northern corn leaf blight and maize head smut and the majority of them have quite good resistance against these three major diseases. In general, the level of disease-resistant maize breeding in Sichuan Province is improving continuously.3. In last 20 years, the maize hybrids bred in Sichuan Province has no dramatic changes in grain size and quality character. Their protein and starch contents have no obvious change and only the fat contents have a slight increase as the breeding years shift.4. Compared with inbred lines bred in 1980s, Sichuan’s inbred lines bred in 1990s have no major changes in respect of growth and development period, ear length, the number of line-kernel and have a slight decrease in the height of plant and the number of ear-lines, however, have a tendency of increase in die weight of 1000 kernels. The results of diallel cross analysis show that both general combining abilityand specific combining ability reached an extremely significant level among materials on trial. There exists diversity of combining ability among 30 inbred lines and the difference of genera更多还原