赣中北“油稻稻”三熟制下头季稻叶片衰老频度对再生稻再生力的影响

为研究三熟制条件下适合种植的再生稻品种及头季叶片衰老频度对再生力特性的影响,在大田试验条件下,以10个杂交水稻品种为材料,比较分析了这些品种的再生力、再生季产量及头季衰老强度等若干性状。结果表明,头季不同品种结实率与再生季再生力呈正相关关系,相关系数为0.620,头季千粒重、叶干质量下降率、叶绿素含量下降率、产量与再生季再生力呈负相关关系,相关系数分别为-0.522、-0.516、-0.637、-0.676。再生季有效穗数与再生力呈显著正相关关系,与活芽率呈负相关,相关系数分别为0.757和-0.615。头季结实率、叶片叶绿素含量、产量,以及再生季有效穗数和千粒重是影响再生力的重要因素。综合两季产量和再生力特性来看,深两优5814、C两优608、准两优608、丰两优香1号等4个品种可以作为再生稻在江西中北部的三熟制条件下种植。     

冬小麦高花药培养力基因型的筛选

为了筛选小麦花培育种骨干亲本,减轻花培育种的基因型依赖性问题,对74个冬小麦品种(系)的5个花药培养力性状进行了鉴定,并对5个性状进行了相关性分析。结果表明,74个基因型的愈伤组织诱导率、绿苗分化率、绿苗产率、白苗分化率及白苗产率变化范围分别为0~43.17%、0~139.29%、0~20.83%、0~63.33%、0~7.17%,各花药培养力性状在所研究基因型中差异明显,存在基因型依赖性,其中绿苗分化率基因型间差异最大。基因型愈伤组织诱导特性与绿苗、白苗的分化正相关,愈伤再生分化成绿苗或是白苗没有相关性。筛选出绿苗产率高于1.0%的基因型22个,其中,SPLM2、衡96851、石4185、邯6172、河农6425五个基因型农艺性状较好,绿苗产率依次为8.17%、5.44%、2.39%、2.00%、0.72%,可作为花培育种的骨干亲本。     

Genetic analysis of early-maturing maize (Zea Mays L.) inbred lines under stress and nonstress conditions

Early-maturing maize (Zea Mays L.) germplasm developed from diverse sources has the potential for use in developing maize hybrids suitable for increasing maize production in the dry ecologies of eastern Africa. A diallel study was conducted to estimate general combining ability (GCA) of 12 early-maturing maize inbred lines, identify potential single-cross hybrids for use as parents, assess genetic diversity among the inbred lines, and relate genetic distance to specific combining ability (SCA) and hybrid performance. Sixty-six F₁ diallel hybrids were evaluated under optimal and drought stress conditions at four locations in Kenya and Uganda. The parental inbred lines were genotyped using 94 single nucleotide polymorphism (SNP) markers. Additive gene action was more important than nonadditive gene action for inheritance of grain yield (GY) under optimal conditions. However, nonadditive gene effects were more important in the inheritance of GY under drought and across all environments. Inbred lines CKL0722, VL058014, and CZL0724 were among the best with positive GCA effects for GY across both optimal and drought stress conditions. The correlation between SCA and both genetic distance and F₁ GY was significant under both drought stress and across all environments. Inbred lines with desirable GCA effects for GY and other agronomic traits and hybrids with good performance under both optimal and drought stress conditions are potential parents for development of various types of high-yielding, stress-tolerant, and early-maturing hybrids.     

Phenotypic plasticity of two invasive alien plant species inside a deciduous forest in a strict nature reserve in Italy

ABSTRACT

Invasive alien plant species (IAPs) represent one of the main biological threats to biodiversity worldwide. Information about their phenotypic plasticity are needed to increase awareness about their future invasive potential. A study about phenotypic plasticity in response to contrasting light regimes and its quantification by a plasticity index (PI) of two IAPs (Ailanthus altissima and Robinia pseudoacacia) inside a Strict Nature Reserve was conducted. R. pseudoacacia showed a 70% higher PI, with a strongly greater value at morphological leaf level, associated with a greater ability to survive and grow in forest understory, explaining its greater widespread. Otherwise, A. altissima showed its highest PI at physiological level, which was associated with the ability to colonize and grow in environments with high-light regimes. Based on these results, the conservative management has limited the presence of A. altissima by its lower ability to grow in forest understory. In fact, the small-scale gaps in the forest infrastructure, that could allow its recruitment, are originated only from the death of a single tree or small group of trees. Regarding R. pseudoacacia, it is critical to maintain this type of management because any disturbances resulting in large openings could further promote its presence inside the Reserve.     

基于实习基地建设的园林专业实践能力协同培养模式探索

园林专业具有实践性强的特点。建设实习基地的过程,可以作为园林专业多门课程的实践教学任务,有利于全方位地训练学生的实操能力。将不同课程的实验集中整合在实习基地建设的过程中,协同培养园林专业学生的实践能力。实践表明,该培养模式可以串联多门专业课程,并整合相关课程中重复的实践教学内容。有助于师生之间加强沟通,教学相长,并显著提升学生的学习兴趣和专业综合能力。     

玉米自交系414配合力及杂优模式分析

414又名(4A、A6),是江苏沿江地区农业科学研究所利用国内外优良自交系,采用独创的“分离小群体选系”方法育成的早熟紧凑型玉米自交系[1]。以其作亲本,先后育成苏玉8号、苏玉9号、苏玉10号、苏玉13号和苏玉14号5个玉米新品种,占江苏自育饲用玉米品种数的1/4左右。其中苏玉9号(414×812)“九五”期间在生产上累计种植2×106hm2,获2001年江苏省科技进步二等奖;苏玉10号(414×75)先后通过国家和江苏省农作物品种审定委员会审定,现正在江苏省及中国东南玉米种植区大面积应用。414已成为江苏玉米育种与生产上最重要的自交系之一。为此,有必要探…     

籼型两系杂交稻主要农艺性状配合力及遗传力分析

用我国新近育成的10个光温敏核不育水稻和3个优良恢复系按NCⅡ交配设计,对11个主要农艺性状的配合力及遗传力进行分析。结果表明:①除单株穗数、千粒重、单株产量、相对日产量的非加性效应不明显外,其他性状加性和非加性效应均有显著作用,且均以加性效应为主,但穗长、每穗总粒数、着粒密度3个性状的非加性效应较大。②F1大多数农艺性状受不育系影响比恢复系大,仅株高、每穗总粒数、千粒重等受恢复系的影响较大。③不育系以208S、培矮64S和02-142最好,恢复系以扬稻6号最好,其次是E 32和宁108。④11个农艺性状遗传力由大到小依次为播始历期、株高、结实率、每穗实粒数、相对日产量、千粒重、穗长、着粒密度、每穗总粒数、单株产量、单株穗数。     

新转萝卜雄性不育系主要性状的配合力分析

采用不完全双列杂交法.对新转育成的5个雄性不育系和3个测验种的5个主要性状根质量、根长、株高、叶片质量、开展度的一般配合力和特殊配合力及遗传力进行了研究.结果表明,雄性不育系A1,A3和测验种S1的根质量、根长、株高、叶片质量、开展度5个农艺性状的一般配合力均较高,是杂交育种的理想亲本,而其他亲本则一般配合力较低;A1×S1,A1×S2,A2×S2,A3×S2,A5×S1和A5×S1等7个组合主要性状的特殊配合力效应值除了个别性状外均为正值,说明其用于杂种优势育种的可行性比较大.遗传力分析表明,除开展度外,其余主要性状均主要受基因加性效应影响,能真实遗传.     

丝瓜自交系主要经济性状配合力及遗传参数分析

按双列杂交设计,用Griffing分析方法,对6个丝瓜自交系的10个主要经济性状的配合力及遗传参数进行分析.结果表明:各性状的一般配合力方差和特殊配合力方差均达到极显著水平.P3和P6自交系的综合性状较优,可在育种中直接利用;P3×P4等4个组合具有较强的杂种优势,有一定的增产潜力.在育种工作中,对丝瓜第1雌花节位等3个性状宜早代选择,而对可溶性糖含量等其它性状应进行晚代选择.     

Specific dynamic action in two body size groups of the southern catfish (<Emphasis Type="Italic">Silurus meridionalis</Emphasis>) fed diets differing in carbohydrate and lipid contents

Specific dynamic action (SDA), the energy costs associated with meal digestion and assimilation, is generally affected by body size and food composition. We assessed the postprandial metabolic response and calculated SDA in two size groups of the southern catfish (Silurus meridionalis), each fed one of two diets, high lipid or high carbohydrate, at a meal size of 4% the body mass. Using a continuous-flow respirometer, we determined the oxygen consumption rate at 2-h intervals until the postprandial oxygen consumption rate returned to the prefeeding level. None of the parameters (resting metabolic rate, Rpeak, factorial ratio, time-to-peak, duration, energy expended on SDA, or SDA coefficient) were significantly affected by diet nor was there an interaction between diet and body mass. Rpeak and energy expended on SDA for the whole fish body were significantly higher in the larger fish than the smaller one in both dietary treatments, whereas no significant effect of body size was found in mass specific values. Factorial ratio (range 3.41 to 3.60), peak time (range 9.6 to 12.7 h), SDA coefficient (range 9.36 to 10.36%), and SDA duration (range 62.0 to 71.0 h) did not significantly differ between body size groups. These results suggest that in S. meridionalis the percentage of assimilated energy allocated to SDA may be independent of the body mass.