云南稻核心种质苗期与孕穗期耐冷性特点及关系分析

以544份云南地方稻核心种质为材料,在昆明自然低温(苗期平均5.5～12.3℃,孕穗期平均17.8℃)冷害下,按籼粳、稻作区进行云南稻核心种质苗期耐冷性与孕穗期耐冷性的特点及关系研究.结果表明:(1)苗期耐冷性与孕穗期耐冷性密切相关,苗期耐冷性强的材料表现为孕穗期株高、剑叶长和宽、穗颈长、穗下节长、1～2节长、穗长较长、穗粒数较多,耐冷性较强.通过对苗期耐冷性的严格选择,可以间接获得孕穗期耐冷性较强的材料.(2)苗期和孕穗期耐冷性在籼粳间、稻作区间差异明显.籼粳间均表现为粳稻强于籼稻;稻作区间苗期耐冷性为滇中一季籼粳稻区和滇南单双季籼稻区最强,滇中一季籼粳稻区和滇西北高寒粳稻区孕穗期耐冷性较强,揭示了水稻苗期与穗期耐冷性的形成演化机制存在一致性和差异性.     

云南粳稻核心种质杂种后代孕穗期耐冷性研究

以236份云南地方粳稻核心种质和云南主栽梗稻Oryza satica品种合系35配制的杂种F5、BC1F4、BC2F3和BC3F2为材料,在昆明自然低温平均17.8℃(冷害)条件下,对亲本及其后代进行孕穗期耐冷性研究.结果表明:①亲本耐冷性状间的相关性明显高于其杂种后代,不同世代间总体趋势为随着回交世代增加其性状间相关性减弱.在亲本及其杂种后代间耐冷指标性状穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率均呈较高的(≥0.370)极显著(n=236,R0.01=0.181)相关.②株高、穗颈长、穗下节长等耐冷性状在亲本强弱耐冷系统群间的差异明显,表现为亲本耐冷性强的材料秆和穗较长、穗粒数较多,同一性状变异程度减小.但随着回交代数的增加,这些性状的平均值逐渐趋同于轮回亲本,差异减小.③穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率在5个稻作区间的变化规律呈现一致性,亲本和F5的差异较大,而BC2F4、BC2F3和BC3F2的差异较小,且趋同于轮回亲本.通过连续回交,在BC3F1即可获得耐冷性状表现良好的材料.     

云南稻核心种质F2主要形态性状变异及地理生态研究

种质资源是水稻育种的重要基因来源.掌握育种材料遗传背景信息,可为发掘优异种质,选育优良性状新品种提供依据.以548份云南稻核心种和云南主栽籼稻品利慎屯502(Oryza satica)、粳稻品种合系35(Oryzasatica)配制的杂种F2(498份)为材料,采用群体遗传学的方法,研究云南稻核心种质杂种F2代的11个形态性状的综合变异系数、遗传多样性指数(Shannon指数)及其地理分布.结果表明:(1)F2存在明显的性状分化和遗传变异,以有效穗、穗颈长、穗下节长、每穗实粒数、秕粒数、总粒数和结实率的综合变异系数高,遗传多样性丰富;(2)滇西南(临沧、思茅、德宏、西双版纳)和滇东南(文山、红河)的材料在表型性状上存在更大的分化,综合变异系数高,遗传多样性丰富;保山、昭通、曲靖次之;怒江、丽江、迪庆、大理最低.     

云南稻核心种质苗期耐冷性及其地理生态差异

采用Nagamine等(1991)法研究了598份云南稻核心种质在稻作区划间、地州间苗期耐冷性强弱、变异程度及其地理生态差异。结果表明,稻作区划间苗期耐冷强弱差异较大,平均耐冷级别为:I(4.70)>II(4.78)>V(4.79)>III(5.34)>IV(5.36),40份强耐冷种质频率为II(45%)>I(25%)>III(22.5%)>V(5.0%)>IV(2.5%),其变异系数为II(32.22%)>I(31.28%)>V(29.65%)>III(19.66%)>IV(19.59%);揭示了苗期耐冷性与低温胁迫下水稻冬春育秧、冷泉水密切相关,其耐冷基因源是云南南部地区冬季育秧和滇中一带苗期倒春寒长期协同进化的结果;苗期耐冷种质广泛存在于热带、亚热带和温带地区,品种间苗期耐冷差异也明显。云南稻核心种质16个地州平均苗期耐冷强弱差异较大。根据气候、生态、云南稻种多样性及其苗期耐冷性等将云南稻作区划分为重冷害多样性贫乏区、冷害多样性中区和轻冷害区三部分。其中,曲靖、大理、楚雄、昆明和丽江5个地州平均耐冷级别3.65~4.32,0—2级苗期强耐冷种质占27.5%(2.5%~10%)和高海拔冷泉水苗期灌溉,属于重冷害多样性贫乏区;文山、红河、思茅、保山、德宏和临沧6个地州平均耐冷级别4.45~5.40,0—2级苗期耐冷种质占70%(5%~30%)和冬春育秧,属于冷害多样性中区;怒江、玉溪、昭通、迪庆和西双版纳5个地州平均耐冷级别5.05~5.87,0—2级苗期耐冷种质占2.5%(0~2.5%),属于轻冷害多样性扩散区。水稻冬春育秧和高海拔冷泉水灌溉在云南稻核心种质苗期耐冷基因源演化中起了重要作用。     

云南籼稻核心种质回交后代苗期耐冷性研究

早春低温和连续阴雨是导致籼稻烂秧的主要因素之一,筛选耐冷的种质资源,将耐冷性基因导入高产的籼稻品种之中是防止低温冷害最为经济有效的方法。加强籼籼稻杂交后代的苗期耐冷性研究,可为籼稻耐冷性育种提供条件。以235份云南籼稻核心种质和云南主栽籼稻品种滇屯502(Oryzasatica)配制的杂种F5、BC1F4、BC2F3和BC3F2代为材料,在昆明自然条件下,对亲本及其后代进行苗期(三叶)耐冷性研究。结果表明,(1)不同回交世代与杂种与亲本间的苗期耐冷强弱差异较大,总体趋势为回交供体亲本>F5>BC1F4>BC2F3>BC3F2;揭示了随着回交世代的增加,其回交杂种苗期耐冷性减弱,越来越趋于轮回亲本,在耐冷育种上对回交供体亲本及其早世代材料进行选择更易获得苗期强耐冷材料。(2)同一稻作区,回交供体亲本的苗期耐冷强于杂种后代;稻作区划间,回交供体亲本及杂种F5总趋势相近,滇中一季籼稻粳稻区和滇东北高原粳稻区材料耐冷最强,而BC1F4、BC2F3和BC3F23个回交世代存在一定差异。     

低磷胁迫下云南稻形态性状的氮肥反应

采用盆栽试验每份材料栽2桶,每盆装4 kg低磷酸性红壤(速效磷2.53 mg·kg-1、速效氮156.7 mg·kg-1和pH=6.03),设置不施氮肥(速效氮156.7 mg·kg-1)和施氮肥(速效氮490.0 mg·kg-1)两种处理对539份云南稻核心种质17个形态性状及其相对指标,研究低磷胁迫下云南稻形态性状的氮肥效应结果表明:总体上低磷胁迫下云南稻核心种质籼稻氮效反应明显比粳稻敏感;按氮反应相对指标将云南稻种17形态性状划分为氮反应的强敏感、中敏感、弱敏感和不敏感型四种类型;揭示了低磷胁迫下云南稻种氮高效鉴定指标以相对穗干质量和相对总干质量为主,相对穗长、秆干质量、地上干质量、根干质量和茎蘖数可作为参考指标,其中穗干质量为氮反应的强敏感型,总干质量、地上干质量、秆干质量和茎蘖数属中敏感型,根干质量属弱敏感型和穗长属不敏感型.另外,低磷胁迫下云南稻种8个对氮反应敏感相对性状无论是在539份云南稻核心种质及其籼粳亚种间,还是在五个稻作区间总趋势是一致的;既证实了该文提出的低磷胁迫下8个氮反应敏感指标性状是十分可靠的,又揭示了低磷胁迫下5大稻作区氮反应的生态差异和土攘类型多样性是云南成为亚洲栽培稻籼粳分化中心之一的驱动力.     

不同种源地云南稻核心种质主要形态性状的遗传特征

揭示云南稻核心种质资源特性、遗传变异特点,对资源的合理利用,指导育种工作,具有重要的意义.以541份云南稻核心种质为材料,在昆明地区生态条件下对其11个形态性状的遗传参数进行研究.结果表明:所研究的11个形态性状广义遗传力在65?%之间,穗颈长、实粒数、秕粒数和结实率的遗传力最大,且均表现出较大的遗传变异,选择潜力较大; 同一性状的遗传差异籼粳间不明显,而稻作区间则存在一定差异.利用本群体进行新品种选育时,应考虑各形态性状的表现特点和遗传潜力大小.对穗颈长、实粒数和结实率系统选育时,滇中一季籼稻粳稻区、滇南单双季籼稻区和南部边缘水陆稻区3个稻作区的材料选择效果较好.     

云南稻核心种质耐低磷性状与籼粳亚种间的关系

在土壤有效磷含量6．26mg／kg和40mg／kg条件下对548份云南地方稻核心种质进行形态性状与籼粳亚种鉴别性状间的耐低磷特性研究．以明确籼粳亚种及其中间型耐低磷特性有无明显差异以及耐低磷特性和籼粳分化相互关系。结果表明：（1）相对分蘖力、相对有效穗、相对总干物质量和相对地下干物质量4个耐低磷指标性状可作为水稻耐低磷能力强弱评价的理想指标；低磷胁迫下耐低磷指标性状可作为水稻磷高效基因型筛选指标。（2）云南稻核心种质由95份籼、178份偏籼、85份偏粳和190份粳稻组成．籼粳亚种间平均耐低磷能力存在明显差异：相对分蘖力、有效穗、地下干物质量、总干物质量平均值由大到小依次为籼、偏籼、偏粳、粳．耐低磷能力随程氏指数的增大，呈现递减趋势。（3）云南稻核心种质6个籼粳分类性状和耐低磷指标性状多数呈显著负相关．耐低磷特性和籼粳分化密切相关。     

水稻磷高效重组自交系群体的筛选鉴定

水稻耐低磷RILs群体培育可为磷高效育种和基因定位提供材料.该试验利用强耐低磷杂交组合合系41×大白稻产生的永久性重组自交系(RILs)群体,设低磷(有效磷6.26 mg·kg-1)胁迫和非低磷(有效磷40 mg·kg-1)胁迫两种处理,全生育期测定了相关的耐低磷形态性状,利用相关分析和多元逐步回归分析等方法探索RILs群体耐低磷筛选指标以筛选优良株系.结果表明:(1)12个主要农艺性状均呈连续性变异, 耐低磷性状发生了明显的重组和分离,说明利用重组近交系可以筛选并培育出强耐低磷的水稻品系.重组近交系是水稻耐低磷特性进行遗传研究的良好材料;(2)6个相对性状:株穗产量、地上干物质量、实粒数、有效穗、剑叶长、穗长,综合评价RIL 群体各株系的耐低磷强弱;(3)在RILs群体选出综合性状表现优良的5个大穗、大粒的耐低磷株系,具有良好的推广前景.     

云南稻种磷高效特性相关性状的生态差异

云南不仅是世界稻种(Oryza sativa L.)最大的遗传和生态多样性中心之一,也是中国土壤类型最丰富的地区;中国南方和云南耕地65%以上缺乏有效磷,土壤缺磷已成为稻作生产的主要限制因子.该文中,缺磷(速效磷6.26 mg·kg-1)与适磷(速效磷40 mg·kg-1)酸性红壤进行比较,以相对茎蘖数(RTA)、相对总质量(RTB)、相对地上质量(RDWU)和相对地下质量(RDWG)为参数,研究了来自云南省16个州市5个稻作区577份水稻核心种质的磷高效基因型及其生态差异,结果表明:低磷胁迫下云南稻核心种质的相对茎蘖数、相对总质量、相对地上质量和相对地下质量密切相关,这4个性状是水稻磷高效鉴定较可靠和方便的指标,并筛选出10个磷高效品种;磷高效基因型在籼粳间存在较大差异,但丁颖分类性状中的水陆、粘糯间差异较小;水稻磷高效品种广泛分布于5个稻作区和绝大多数州市,特别是磷高效极强品种主要来自云南稻种的遗传多样性中心(思茅、临沧、西双版纳、德宏和文山州)和基因多样性中心(南部边缘水陆兼作区).这些结果有力地支持了水稻磷高效特性与酸性红壤和遗传多样性中心有关,更好地理解水稻磷高效特性的地理生态和遗传多样性机制.     

Association studies for agro-physiological and quality traits of triticale x bread wheat derivatives in relation to drought and cold stress

Correlation coefficient analysis conducted on 22 triticale x bread wheat derivatives along with six checks to select true- breeding derivative(s) for future hybridization programme with tolerance to drought and cold stress conditions as well as better quality traits revealed significant correlation of grain yield with spikelets per spike, biological yield, harvest index, leaf area index. Interestingly, the grain yield and drought susceptibility index showed no association. However, with cold tolerance it showed significant positive correlation indicating the desirability of certain plant traits under cold stress. The grain yield exhibited no association with quality traits which might assist in the predictability of high yielding varieties with high protein, total sugars, reducing sugars and non-reducing sugars. Path coefficient analysis revealed that biological yield had the highest positive direct effect on grain yield followed by harvest index, specific leaf weight, stomatal number, 1000 grain weight, stomatal size, spikelets per spike and days to heading. Therefore, indirect selection for these plant traits in order should be exercised in selecting drought tolerant genotypes. Two genotypes (RL-124-2P2 and RL 111P2) were found to be drought and cold tolerant with high grain yield, spikes per plant, spikelets per spike and leaf area index.     

不同强度冷刺激对大鼠心脏、大脑、睾丸和肺脏中CIRP表达的影响

采用Western blot和实时荧光定量RT-PCR方法,研究不同强度不同时间冷刺激后大鼠心脏、大脑、睾丸和肺脏中冷诱导RNA结合蛋白(CIRP)的表达情况.结果表明:常温(20℃±1℃)下大鼠4种组织中均存在一定的CIRP的表达;急性冷刺激组(-10℃±1℃、-4℃±1℃、0℃±1℃、4℃±1℃)心脏、大脑和睾丸中CIRP mRNA表达在冷刺激0～6 h呈上升趋势,6 h时达到最高值,随后呈下降趋势,肺脏中CIRP mRNA表达在0～6 h呈下降趋势,在6 h时达到最低值,随后呈上升趋势;慢性冷应激组(10℃±1℃)大鼠心脏、大脑和睾丸3种组织中CIRP mRNA在不同时间点(1周、2周、3 W周)的表达均高于正常对照组(P>0.05),肺脏CIRP mRNA表达均低于对照组(P>0.05),并且同一组织不同时间点之间差异不显著(P>0.05).可见冷刺激后CIRP的表达存在一定规律并且表现出组织特异性,可能与组织保护特异性有关.     

Estimates of Natural Selection in a Salmon Population in Captive and Natural Environments

Abstract:  Captive breeding is a commonly used strategy for species conservation. One risk of captive breeding is domestication selection—selection for traits that are advantageous in captivity but deleterious in the wild. Domestication selection is of particular concern for species that are bred in captivity for many generations and that have a high potential to interbreed with wild populations. Domestication is understood conceptually at a broad level, but relatively little is known about how natural selection differs empirically between wild and captive environments. We used genetic parentage analysis to measure natural selection on time of migration, weight, and morphology for a coho salmon ( Oncorhynchus kisutch ) population that was subdivided into captive and natural components. Our goal was to determine whether natural selection acting on the traits we measured differed significantly between the captive and natural environments. For males, larger individuals were favored in both the captive and natural environments in all years of the study, indicating that selection on these traits in captivity was similar to that in the wild. For females, selection on weight was significantly stronger in the natural environment than in the captive environment in 1 year and similar in the 2 environments in 2 other years. In both environments, there was evidence of selection for later time of return for both males and females. Selection on measured traits other than weight and run timing was relatively weak. Our results are a concrete example of how estimates of natural selection during captivity can be used to evaluate this common risk of captive breeding programs.     

盐碱胁迫对水稻主要生育性状的影响

对7个水稻品种(品系)和苏打盐碱土(pH6．5～19．81)进行盆栽试验，探讨了盐碱胁迫对水稻株高、秆长、分蘖和抽穗期等主要生育性状的影响。结果表明，盐碱胁迫使水稻株高降低、秆长缩短，且盐碱度越大，降低幅度越大；盐碱胁迫使水稻单株分蘖力明显下降，使分蘖高峰明显推迟或不出现分蘖高峰；水稻抽穗期随着盐碱度的提高，其延长的天数越长，并且发现不耐盐碱的早熟品种比耐盐碱的中晚熟品种抽穗晚；水稻成熟期的株高或秆长不宜作为衡量其耐盐碱强弱的主要指标，只能作为一般参考指标。水稻单株分蘖力(茎蘖数)和抽穗期存在明显的基因型差异，是衡量水稻耐盐碱强弱的良好指标。盐碱地种稻应重视选择单株分蘖力较强的耐盐碱品种，这对提高单位面积的有效穗数具有十分重要的意义。     

Metabolic variation in rice cultivars of contrasting salt tolerance and its improvement by zinc in sodic soil

The severity of Zn deficiency increased with increase in soil exchangeable sodium percentage (ESP) with salt sensitive variety M1-48 scoring 6 at ESP 62 as against only score 3 by salt tolerant variety Pokkali under similar soil conditions. Strikingly, zinc contents were much higher in salt tolerant variety than in salt sensitive one. Zinc application increased zinc concentration in the roots by a factor of 2.85 to 3.87 in Pokkali whereas it rose from 2.37 to 4.35 times in M1-48 depending upon ESP but in the leaves it registered increase of 1.5 to 1.8 times only. In general, the concentrations of reducing sugar were less (about 2.2%) than that of non-reducing (about 3.8%) in both the varieties under normal soil conditions. However, the concentration of reducing sugar doubled (4.2-4.4%) at the highest ESP 62, whereas the concentration of non-reducing sugar though increased (4.1 to 5.1%) but not as vigorously as reducing one. Zinc application reduced the concentration of reducing sugar but not that of non-reducing at similar ESP values. In Pokkali, the concentrations of total sugar increased from 6% at ESP 20 to 9.34% at ESP 62, whereas it registered enhancements of 5.98 to 8.6% in M1-48 under similar conditions. The nitrate reductase (NR) activity decreased with increase in soil sodicity however, the varietal differences in NR activity were wider under Zn-stress than under conditions of applied zinc with Pokkali registering higher NR activities. Carbonic anhydrase activities were higher in salt tolerant variety. Inhibition in carbonic anhydrase activity amounted to 23 and 45% in salt-sensitive variely M1-48 whereas only 19 and 33% in salt-tolerant variety Pokkali at ESP 41 and 62, respectively. The effects of zinc application at higher soil sodicity were more obvious in salt-sensitive variety than in salt-tolerant one. The findings suggest that the tolerance to Zn stress runs parallel to salt tolerance abilities of rice varieties.     

Genetic experssion of temperature tolerance in the copepod Eurytemora affinis in different salinity and temperature environments

The genetic expression of temperature tolerance in Eurytemora affinis Poppe in different environments was investigated by testing temperature tolerances of broods in pairs of salinity and temperature environments. Three methods were used to identify interaction between genotype and environment: (1) the correlation between mean tolerances of halves of broods grown in the two environments, (2) brood by environment interaction and (3) heritabilities in the two environments. All correlations between means of half broods were positive, only one of six brood by environment interactions was significant and the heritability estimates were not markedly different. Thus, the variability in temperature tolerance in different salinities and in different temperatures seems to be due to the same genes; and selection pressure on temperature tolerance is in the same direction with seasonal changes in temperature and salinity.     

不同虫压下转Bt基因水稻与非转基因水稻生态适合度差异

为了解转基因水稻的基因扩散效率和潜在生态风险,以转Bt抗虫水稻Bt63、R1、R2和非转基因常规水稻Ⅱ优838为试材,采用高、低两个不同虫害胁迫水平和转基因与非转基因水稻相间种植方式,通过观察水稻植株营养生长、结实以及对螟虫危害的抗性表现等差异,研究比较了Bt外源基因插入后对水稻植株适合度的影响.结果表明:在低虫害胁迫条件下,转Bt基因水稻在植株分蘖数、生物量鲜重等营养生长指标方面与非转基因对照品系间无明显差异,但株高、穗长、穗重等指标不及对照,且R2和Bt63与对照间差异显著;在高虫害胁迫条件下,3个转Bt基因水稻品系的分蘖数、穗长、穗重等指标明显高于对照.而不同转基因品系株高适合度效应不同,这可能与受体本身的特性相关.3种转基因水稻的单株结实粒数、千粒重与对照在两种虫害胁迫条件下均无显著性差异,Bt基因对受体植株的结实影响不明显.在高虫害胁迫条件下,3种转Bt基因水稻的抗虫能力均显著优于非转基因水稻,表明Bt基因对受体植株的抗虫性影响显著.同时,本研究结果还表明转Bt基因水稻的适合度代价较小,预示了抗虫转基因水稻外源Bt基因在一定环境条件下具有逃逸的可能,但这种风险比较小.     

低磷胁迫下大麦磷高效基因型的筛选

为获得大麦（Hordeumv ulgare Linn.）磷高效育种的材料,分别在土壤有效磷质量分数为1.32和36.6mg·kg-1的条件下,对180个大麦品种进行磷高效材料的筛选和鉴定研究。结果发现,不同品种中磷高效差异很大;中国大麦茎干重和地上重极显著高于美国大麦（P=0.000）;裸大麦（H.vulgare var.nudum）有效穗、分蘖数和茎干重极显著高于皮大麦（H.oldeum vulgateL.）;多棱大麦（Hordeum vulgareL.）分蘖数、茎干重和地上干重极显著高于二棱大麦（Hordeum distichon L.）。磷效率用耐低磷力和品种适应性来描述,用籽粒产量计算耐低磷力,云啤1号（122.3%,231.43%）、Z050P004Q（109.81%,214.40%）和YS500（101.08%,566.14%）等是供试样品中磷高效较高的品种。该实验结果为云南地区进一步选育磷高效的大麦品种提供了材料。     

Relatedness and environment affect traits associated with invasive and noninvasive introduced Commelinaceae.

Understanding the traits of invasive species may improve the ability to predict, prevent, and manage invasions. I compared morphological and performance traits of five congeneric pairs of invasive and noninvasive Commelinaceae across a factorial experiment using a range of water and nutrient availabilities. Invasive species had greater fecundity and vegetative reproduction than their noninvasive relatives. The invasive species also had higher relative growth rates, greater specific leaf area, and more plastic root-to-shoot ratios than noninvasive species. However, whether a trait was associated with invasiveness often depended on both environment and relatedness. Invasives had greater sexual and vegetative reproduction, higher specific leaf area, and greater relative growth rates than noninvasive congeners, but only in some environments. Differences between invasive and noninvasive taxa were greatest at high nutrient availabilities. These results suggest that studies of invasive species' traits must incorporate information on conditions under which the trait was measured. In addition, incorporating information on relatedness improved our ability to detect associations between species traits, such as specific leaf area and relative growth rate, and invasiveness, suggesting that such information may be required for a complete understanding of what makes a species invasive.     

Upper temperature tolerances of Tellina tenuis and T. fabula

The upper lethal tolerances of Tellina tenuis da Costa and T. fabula Gmelin were studied under a variety of temperature regimes in which both short-term and long-term mortality were noted; these included steady temperatures, acclimation at a steady temperature then exposure to a steady tempeature, and acclimation at gradually increasing temperatures. T. tenuis alone was also tested for variation in mortality rate according to the date of collection or to the size (i.e., age) of the mollusc. The results suggested that T. tenuis was consistently more tolerant than T. fabula, and that the difference in tolerance was around 5 C°. Both species readily acclimated to higher temperatures after steady temperature acclimation, but not under a regime of gradually increasing temperature. There was no significant, variation in the mortality rate of T. tenuis with season or age. It is suggested that, since the difference in temperature tolerance is not reflected in their respective geographical distributions, there may be some other stage in their life cycle, e.g. the larvae, which is equally susceptible to temperature extremes. The difference in tolerance is, however, reflected in their respective littoral and sublittoral distributions.