不同热带、亚热带玉米种质在温带和热带地区种植比较研究

自1989年以来对S901等19份热带、亚热带玉米材料,先后进行温带(河南安阳)、热带(海南岛)种植鉴定,结果表明:(1)供试的19份材料中仅筛选出S901、S902、S903、S905等材料,其主要农艺性状均表现相对稳定、一致,生理生化代谢,对光周期反应不敏感。并表现出较强的抗逆性和适应性。能够在温带地区种植利用,并可以直接应用于玉米遗传育种研究。(2)S904、S906、S908、S909、S910等材料在主要农艺性状上均表现出较大的差异。生理生化代谢失调,多数植物学、生物学性状发生改变,稳定性、一致性差,对光周期反应十分敏感。抗病性、适应性差。不适应在温带地区种植,更不能直接用作育种材料。只可以间接利用其个别优良性状。     

Large-scale screening for maize drought resistance using multiple selection criteria evaluated under water-stressed and well-watered environments

A total of 550 maize inbred lines collected from global breeding programs were evaluated for drought resistance under both well-watered and water-stressed environments. The evaluation was based on multiple measurements of biomass taken before and after the drought stress was applied using the normalized difference vegetation index (NDVI), along with other selection criteria including anthesis-silking interval, leaf senescence, chlorophyll content, root capacitance, final grain yield, and grain yield components. Kernel weight was the most stable trait under drought stress. Correlations between the primary trait (grain yield) and the secondary traits, except the root capacitance and ASI under water-stressed condition, were all significant. Root capacitance had relatively low heritability and low genetic correlation with other drought resistance criteria, and is not recommended as a drought resistance criterion. Significant reduction of NDVI values measured in the afternoon when the leaves became rolling, compared to those measured in the morning when the leaves were open, provides a reliable index for leaf rolling, which however was not significantly correlated with grain yield. NDVIs measured across different developmental stages were highly correlated with each other and with most of the secondary traits as well as, grain yield, indicating that NDVI can be used as a secondary trait for large-scale drought resistance screening. Regression models built based on non-yield drought criteria and yield components explained about 40% and 95% of the variation for the grain yield, respectively. Some maize lines developed in China for temperate regions showed strong drought resistance comparable to tropical maize lines when tested under tropical condition, indicating that temperate lines with a wide adaptability can be used in drought resistance breeding for both temperate and tropical environments.     

Coping with continuous human disturbance in the wild: insights from penguin heart rate response to various stressors

ABSTRACT: BACKGROUND: A central question for ecologists is the extent to which anthropogenic disturbances (e.g. tourism) might impact wildlife and affect the systems under study. From a research perspective, identifying the effects of human disturbance caused by research-related activities is crucial in order to understand and account for potential biases and derive appropriate conclusions from the data. RESULTS: Here, we document a case of biological adjustment to chronic human disturbance in a colonial seabird, the king penguin (Aptenodytes patagonicus), breeding on remote and protected islands of the Southern ocean. Using heart rate (HR) as a measure of the stress response, we show that, in a colony with areas exposed to the continuous presence of humans (including scientists) for over 50 years, penguins have adjusted to human disturbance and habituated to certain, but not all, types of stressors. When compared to birds breeding in relatively undisturbed areas, birds in areas of high chronic human disturbance were found to exhibit attenuated HR responses to acute anthropogenic stressors of low-intensity (i.e. sounds or human approaches) to which they had been subjected intensely over the years. However, such attenuation was not apparent for high-intensity stressors (i.e. captures for scientific research) which only a few individuals experience each year. CONCLUSIONS: Habituation to anthropogenic sounds/approaches could be an adaptation to deal with chronic innocuous stressors, and beneficial from a research perspective. Alternately, whether penguins have actually habituated to anthropogenic disturbances over time or whether human presence has driven the directional selection of human-tolerant phenotypes, remains an open question with profound ecological and conservation implications, and emphasizes the need for more knowledge on the effects of human disturbance on long-term studied populations.     

Inter-individual consistency in habitat selection patterns and spatial range constraints of female little bustards during the non-breeding season

Background

Identifying the factors that affect ranging behavior of animals is a central issue to ecology and an essential tool for designing effective conservation policies. This knowledge provides the information needed to predict the consequences of land-use change on species habitat use, especially in areas subject to major habitat transformations, such as agricultural landscapes. We evaluate inter-individual variation relative to environmental predictors and spatial constraints in limiting ranging behavior of female little bustards (Tetrax tetrax) in the non-breeding season. Our analyses were based on 11 females tracked with GPS during 5 years in northeastern Spain. We conducted deviance partitioning analyses based on different sets of generalized linear mixed models constructed with environmental variables and spatial filters obtained by eigenvector mapping, while controlling for temporal and inter-individual variation.

Results

The occurrence probability of female little bustards in response to environmental variables and spatial filters within the non-breeding range exhibited inter-individual consistency. Pure spatial factors and joint spatial-habitat factors explained most of the variance in the models. Spatial predictors representing aggregation patterns at?~?18 km and 3–5 km respectively had a high importance in female occurrence. However, pure habitat effects were also identified. Terrain slope, alfalfa, corn stubble and irrigated cereal stubble availability were the variables that most contributed to environmental models. Overall, models revealed a non-linear negative effect of slope and positive effects of intermediate values of alfalfa and corn stubble availability. High levels of cereal stubble in irrigated land and roads had also a positive effect on occurrence at the population level.

Conclusions

Our results provide evidence that female little bustard ranging behavior was spatially constrained beyond environmental variables during the non-breeding season. This pattern may result from different not mutually exclusive processes, such as cost–benefit balances of animal movement, configurational heterogeneity of environment or from high site fidelity and conspecific attraction. Measures aimed at keeping alfalfa availability and habitat heterogeneity in open landscapes and flat terrains, in safe places close to breeding grounds, could contribute to protect little bustard populations during the non-breeding season.

     

Variations in Bran Carotenoid Levels within and between Rice Subgroups

Rice (Oryza sativa L.) is a major grain in the human diet and carotenoids are valuable antioxidants. However, little is known about varietal differences in the carotenoid contents of the rice bran. The objective of this study is to determine the relative differences in bran carotenoid levels among all the five subgroups of rice. Measurements were made by a recently described, rapid non-destructive fluorescence quenching method. Confirmation by high performance liquid chromatography (HPLC) after solvent extraction of the bran indicated that the major carotenoid was lutein. Our data showed that carotenoid levels were stable over 10 years of storage. Tropical japonica rice, the most consumed subgroup in the United States, tended to have the lowest levels of carotenoids in the bran while temperate japonicas had the highest. These differences in carotenoid content may open up new opportunities for identifying or breeding rice varieties with higher nutritional value.     

Frequency distributions of sward height under sheep grazing

Cattle and sheep can create and maintain a mixture of relatively tall and short patches in grass swards through selective grazing. In swards that are grazed by cattle this heterogeneous structure can result in the frequencies of height measurements having a skewed distribution that has variously been better described by the double‐normal distribution the gamma distribution and the Weibull distribution than by the more common normal distribution. The fit of these statistical distributions, and the adequacy of the potentially useful log‐normal distribution, to sward height frequencies were tested in sown temperate swards grazed by sheep and compared within a single sward. It was concluded that the single‐normal and Weibull distributions were inadequate and that overall the log‐normal and gamma distributions had the best fit to the measurements.     

成株期抗纹枯病小麦种质的发掘

小麦纹枯病是一种危害小麦茎基部的土传真菌病害,近年来在我国长江中下游和黄淮麦区发生日趋严重,限制了小麦的高产稳产。当前生产上推广品种对纹枯病的抗性普遍较差且抗病育种进展缓慢,究其主要原因是纹枯病抗源匮乏。为发掘小麦纹枯病稳定抗源,本研究采用土表接菌法和滚动鉴定的方式,连续10年在3个环境(南京大田、六合大棚和水泥池)下,对共计384份小麦种质资源进行了成株期纹枯病抗性鉴定。结果表明,携带小麦近缘种属遗传物质的近缘种质抗性较好,国外引进种质次之,国内育成品种(系)抗性较差。鉴定出成株期对纹枯病呈稳定抗性的种质3份,分别为小黑麦09R1-29、美国引进种质Glacier和Steele;鉴定出呈稳定中抗的种质44份,包括淮麦920等育成品种(系)11份,辉县红等地方品种2份,Scout等引进种质11份,来源于黑麦、簇毛麦、偃麦草、人工合成小麦等的近缘种质20份。这些小麦成株期纹枯病新抗源可为抗纹枯病研究和抗病新品种培育提供种质资源。     

Genome-Wide Association Studies Reveal New Genetic Targets for Five Panicle Traits of International Rice Varieties

Narrow genetic background is a key limiting factor in breeding stable high-yielding rice. The introduction and utilization of international rice core germplasm is an important way to increase the genetic diversity of domestic rice varieties. We conducted a genome-wide association study on 5 panicle traits of 315 rice accessions introduced from the international rice micro-core germplasm bank. Based on the tests from Yangzhou of China and Arkansas of American, environment exhibited a significant impacts on panicle length and primary branch number, while grain length, grain width and grain length/width ratio were insensitive to environment changes. We discovered a total of 7, 5, 10, 8 and 6 chromosomal regions or single nucleotide polymorphism marker loci that were significantly associated with primary branch number, panicle length, grain length, grain width and grain length/width ratio, respectively. Among them, eleven regions were associated with grain shape and one region associated with primary branch number, showing the good consistence in two different environments. Significant linear correlation was discovered between the average trait value and the number of favorable alleles carried by the varieties in all associated loci. Among the associated loci, varieties in aromatic and tropical japonica sub-groups possessed most favorable alleles, while those in temperate japonica sub-group contained the least. The domestic varieties mainly harbored unfavorable alleles in six of the associated loci being detected. On the contrary, 15 varieties from 11 different countries harbored more favorable alleles(as many as 30 or more) than the others. Remarkably, all these 15 varieties belonged to the tropical japonica sub-group. In conclusion, our study demonstrates that varieties in the tropical japonica sub-group had high potentials for breeding stable high-yielding rice. Based on this discovery, we proposed a new approach for improving the panicle traits of domestic rice by using tropical japonica varieties.     

High Ca and P homeostasis ensure stable forage Ca:P following historical nitrogen inputs in a temperate steppe

Calcium (Ca) and phosphorus (P) are essential nutrients for plant growth, with consequences on ruminant diet and health. Their balance in forage, as indicated by Ca:P ratio, is important for the absorption and utilisation of both elements by livestock. While nitrogen (N) deposition has been globally observed, it is declining or is projected to decline due to controls on N emissions in many countries. It is an open question whether N inputs would have legacy effects on forage Ca and P nutrition in grasslands. Here, we examine the changes of Ca and P concentrations and Ca:P ratio in plants and soils in a temperate steppe for three continuous years (2016 ~ 2018) following historically 6 years N inputs (2008 ~ 2013) with a gradient ranging from 0 to 20 g N m⁻² year⁻¹. Soil extractable Ca concentrations significantly decreased with increasing N addition rates in all the 3 years, but soil available P concentrations increased and Ca:P ratio decreased only in 2016. Ca and P nutrition varied greatly amongst the four plant functional types, but they were generally conservative across the historical N addition rates, due to the high stoichiometric homeostasis. Furthermore, plant Ca and P concentrations and Ca:P ratios at the community level showed no significant variation along the N addition gradient. Our results highlighted the role of plant Ca and P homeostasis in ensuring stable Ca and P nutrition in forage following historical N inputs in temperate grasslands.     

Interactions between commercial fishing vessels and a pelagic seabird in the southern Mediterranean Sea

Background

Fishing activities can influence foraging behaviour of many seabird species worldwide. Seabirds are attracted by fishing vessels which can facilitate access to demersal fish as a novel food resource that otherwise would be unavailable. On the other hand, intense fishing activities cause depletion of fish stocks with a reduction of natural prey available for seabirds. Moreover, fisheries discards can have lower nutritional value than natural prey. However, the importance of fisheries discard for seabirds and the possible implications on their foraging ecology is still poorly understood. In this study, we analysed the interactions of Scopoli’s shearwaters (Calonectris diomedea) during their foraging trips with fishing vessels. We combined the GPS and accelerometer data of shearwaters with the GPS data gathered during the same period from fishing vessels. Accelerometers allowed us to identify the main behaviours of birds.

Results

The presence of fishing vessels significantly affected the individual behaviour of Scopoli’s shearwaters. Birds increased the time spent sitting on the water within 1.28?±?0.13 km of fishing vessels likely feeding or waiting for discards. Approaches towards vessels within the interaction distance were therefore classified as an interaction and were recorded in about 40% of individuals. Birds interacting with fisheries had longer flight time during their foraging trips and covered longer distances to reach more distant foraging areas compared with individuals not approaching vessels.

Conclusions

Our results suggested that fisheries discard consumption might not be a profitable source of food for Scopoli’s shearwaters. Despite the high density of fishing vessels in the home range of Scopoli’s shearwater, most individuals did not interact with them. Accordingly, scavenging individuals showed a lower foraging efficiency than their conspecifics. Intraspecific competition for foraging areas might play an important role for the foraging decision of birds to consume fisheries discards.

     

杂交大豆育种方法和制种技术的实践与研究

本文详细阐述了杂交大豆“三系”选育、杂交种选育、制种技术等内容，“三系”的选育采用已育成的品种或品系与RN型稳定的大豆不育系进行测交和回交转育进行选育，大豆杂交种是利用不育系和恢复系进行大规模配制杂交组合，经过F1产量鉴定，筛选出强优势组合，而制种要求选择干旱少雨、日照充足、有灌溉条件、野生昆虫种类多、群体大的地区。     

抗旱节水型衡麦系列品种的选育方法及系谱分析

为探讨抗旱节水小麦的定向培育方法,对抗旱节水型衡麦系列品种选育过程进行了总结和分析。多年来河北省农林科学院旱作农业研究所围绕"节水抗旱、抗逆高产、广适稳产、优质早熟"的育种目标,着眼解决地下水资源极度匮乏与农业生产矛盾突出的问题,为培育抗旱节水型广适小麦品种,利用常规育种技术与分子标记检测手段,广泛筛选遗传背景远缘且生态差异较大的优异亲本组配组合,创新采用不同世代水旱交替双向综合选择技术,先后育成16个抗旱节水型小麦品种,提高了选择效率和水资源利用率。在系谱上,衡观35等为代表的衡麦系列品种与蚂蚱麦、碧玉麦和洛夫林10号存在一定的血缘关系,且含有对光周期不敏感的Ppd-Dla等优异基因。这些品种目前已由冀中南冬麦区推广至黄淮冬麦区(南、北片)、北部冬麦区(天津)和长江中下游冬麦区(湖北襄阳)等区域种植,展示出生态广适、节水稳产的特点。     

156份小麦种质资源的纹枯病抗性鉴定与评价

为筛选在育种和生产上可利用的纹枯病稳定抗源,采用温室牙签接种法对156份小麦种质资源进行了纹枯病抗性鉴定。结果表明,供试材料存在纹枯病抗性差异,共筛选出36份两年表现稳定中抗及以上的种质材料,包括10份国内改良品种,16份美国引进小麦材料和10份小麦-华山新麦草后代材料。其中,Y-83-1和Y-83-3两年表现稳定抗病,且农艺性状较好,可作为抗小麦纹枯病育种的稳定抗源。     

Screening potato (Solanum) species for male fertility under heat stress

Heat stress limits botanical seed production by inhibiting flowering, pollen production and pollen viability. Three accessions (PIs) of each of 23 diverseSolanum species were screened for stability of fertility parameters under heat stress. Seedlings were grown to flowering in temperate conditions (16–25 C), then treated with three weeks of heat stress of up to 45 C for 4–6 hours per day at midday with nighttime lows of 18 C, and compared to temperate-grown controls. A highly significant effect of species, temperature, and their interaction was detected for flowering. This means species were inherently different and heat had a general depressing effect, but the degree of that effect varied among species. While most species had little flowering in the hot house,S. commersonii andmicrodontum flowered significantly more there than in the temperate house. Of species which flowered in hot conditions, some shed no pollen and some had good shed of mostly dead pollen, but onlyS. commersonii, jamesii, kurtzianum andmegistacrolobum had good flowering, pollen shed and viability. This work is expected to contribute to the study of the genetic and physiological bases of heat stress fertility, true potato seed (TPS) breeding, and possibly improvement of tomato production under heat stress.     

玉米杂交种鲁单718 的选育策略

玉米品种的选育策略决定育种工作的成败。根据目前我国玉米生产实际情况,确定"从拓宽种质基础、丰富遗传多样性入手,改良品种的适应性;把国内种质良好的丰产性与热带、亚热带种质突出的多抗性融合在一起,提高育成品种的多抗性和稳产性能;把成熟早、灌浆快、配合力高、株型紧凑的塘四平头种质与丰产、大穗的旅大红骨种质融合在一起,挖掘育成品种的丰产潜力,改善商品品质"的创新理念,确立"高产、优质、多抗、广适和易制种"的育种目标,结合单倍体快速选系等技术,成功选育出配合力高、抗病抗倒能力强、适应性广的优良自交系齐3925和黄572,杂交育成高产、优质、多抗玉米新杂交种鲁单718。     

云南干热河谷优良牧草的筛选

1999～2011年,针对云南干热河谷自然生态条件,从国内外收集、引进278份牧草资源。根据牧草种质植物学特征和生物学习性,开展了137份牧草资源调查,经生育期、营养价值、生产价值及抗逆性评价,筛选出热研4号王草、红象草、热研8号坚尼草、多花黑麦草、百喜草、新银合欢、木豆、热研2号柱花草、甘农3号紫花苜蓿、提那罗新诺顿豆等一批适应干热河谷种植、应用在本区生态养殖和生态环境建设的优良牧草。这些牧草表现出一定的速生性,生长季生物产量高。其中热带牧草抗逆性强,能够抵御干热河谷高温干旱生态环境;豆科牧草粗蛋白含量     

上海市近10年审定水稻品种分析及育种发展探讨

依据2005-2014年上海市水稻审定品种的区域试验资料,分析了近10年上海市审定水稻品种的基本情况。数据表明,近10年上海市审定水稻品种数量基本稳定;科研院所和区县级农业技术推广服务中心是最主要的育种力量;审定品种产量水平逐年提高,品质提升较快。今后需加强科企合作,发挥科技优势,兼顾高产、优质、适合机械化种植等多个因素,加快上海市商业化育种步伐。     

百色干热河谷地区降雨氢氧稳定同位素特征及芒果树水分来源研究

百色市右江河谷是我国著名的干热河谷之一，干旱是该地区最严重的气象灾害。芒果是该地区地理标志农产品，但其水分利用策略尚不清楚。本文基于氢氧稳定同位素示踪技术研究该地区降雨同位素特征及影响因素，利用多元线性混合模型方法量化不同来源水分对芒果树根系吸水的贡献比例，揭示芒果树生育期内水分利用策略。结果表明：（1）研究区氢氧稳定同位素具有明显的季节变化，δ值和氘盈余（d）具有旱季富集、雨季贫化的规律，建立了研究区的大气降水线方程：δD=8.2587δ18O+12.308,δD和δ18O值有极显著相关性（r=0.9968, n=35, P<0.001）;(2)季风气候影响下大气降水稳定同位素值具有显著的降雨量效应和反温度效应（P<0.05）;(3)在芒果花期、幼果期、果实膨大期和成熟期，土壤水氢氧稳定同位素总体上随土壤深度的增加而变贫；在花期和幼果期，芒果树对各层次土壤水分及地下水利用比例较为均匀，果树膨大期和成熟期则主要利用深层次土壤水及地下水，表明该地区芒果树主要以深层次土壤水及地下水为水源，说明芒果树更接近于保守型水分利用策略。降雨氢氧稳定同位素特征反映了该地区干热的气候特征，芒...     

Variation in polar lipid composition among near-isogenic wheat lines possessing different puroindoline haplotypes

The exact mechanism underlying wheat (Triticum aestivum L.) kernel hardness is unknown. Similar to puroindoline proteins, polar lipids are present on the surface of starch granules. The objective of this research was to determine the specific polar lipid species present on the surface of wheat starch from near-isogenic wheat lines that have different puroindoline haplotypes and endosperm hardness. Four near-isogenic wheat lines were used in this study, all derived from the soft cultivar Alpowa. Direct infusion tandem mass spectrometry was used to identify the lipid species in whole-meal, flour and starch samples. Endosperm hardness had no significant effect on the polar lipid contents in wheat whole-meal, a slight influence on the polar lipid contents of the flour fractions and a significant influence on the polar lipid composition of the polar lipids located on the surface of wheat starch. The greatest quantities of polar lipids on the starch-surface occurred when both puroindoline proteins were present in their wild-type form. Starch-surface polar lipid content dramatically decreased when one of the puroindoline proteins was null or if pin-B was in the mutated form. The least amount of polar lipids was present when pin-B was in its mutated form and pin-A was in its wild-type form.     

利用轮回选择法创造粳稻三系恢复系的研究

利用8份光温敏核不育粳稻材料及28份北方寒冷稻作区优良粳稻品种(系)作为原始亲本开展轮回选择育种,育成了吉粳85、吉524、E180和E385等4个具有三系恢复基因的粳型恢复系。这些恢复系性状稳定,恢复度好,测交F1代产量优势明显,表明轮回选择为粳稻恢复系选育提供了一条新的技术途径,并使三系杂交稻在北方寒冷稻作区的大面积推广成为可能。