春播小麦品质与生育进程和气候条件的关系

1998～2000年,用10个小麦品种在北京进行了3个年度的春播试验,以探讨生育进程和气候条件对品质的影响．结果表明,一些品质性状的品种间差异不显著,而年度间差异显著．播种．成熟天数和籽粒硬度呈极显著负相关．抽穗-成熟天数与籽粒湿面筋含量也呈极显著负相关．抽穗．成熟期间的昼夜温差与籽粒NIR蛋白含量呈显著负相关;总辐射量、昼夜温差与湿面筋含量呈极显著负相关,总日照与湿面筋含量呈极显著正相关;总辐射量、总日照、日均温、昼夜温差与沉降值呈显著负相关．在春播小麦优质栽培中,根据不同需要,既可使用生育期较短的品种,也可使用生育期较长的品种．种植生育期较长的品种时,可与间作、套种结合起来．     

北京地区夏播小麦的生态条件及生育表现

本文探讨了小麦在异常种植条件下的生长发育表现,从面揭示其温光反应规律。 1982—1985年连续三年在北京地区进行的小麦夏播生态试验证明:强春性小麦品种在北京晚夏播种,能很快地顺利出苗,并能抽穗成熟。在高温和长日条件下,它们的生育进程快,植株低矮,千粒重低。在生育早期未出现低温效应,可不发生田间春化反应。此外夏播小麦在科研与生产上都具有一定意义,浮小麦和麦苗都有利用价值。     

墨西哥小麦品种生育期与产量及穗部性状的通径分析

研究了35份墨西哥小麦品种11个性状的遗传相关和通径关系。结果表明,拔节期、开花期不但对成熟期的早晚具有重要作用,而且对每穗粒数和千粒重有重要影响;同时拔节期及抽穗期对墨麦品种小区产量的形成有明显作用。因此墨麦品种的产量除受每穗粒数及千粒重的影响外,拔节、抽穗生长发育阶段的长短也是影响产量高低的重要因素。     

养料供应对麦粒发育的影响及小麦主茎和分蘖间关系

麦粒能够长到多大多重?为了探讨小麦的增产潜力,这个问题有一定的意义。小麦的千粒重被认为是一个品种特性,品种间差异很大。例如我国各地的推广良种中,千粒重轻的如西北54,平原50、蚰子等,只有26—29克,重的如华北187、四川51等,约为40—43克,中等的如华北497,碧蚂1号、石家庄407等,在35克左右(金善宝,1961)。据报导个别杂交种,千粒重有高达65—70克的1953)。同一品种的千粒重随栽培条件的不同而有差异。虽说千粒重在产量构成要素中比较     

遮荫对水稻生长发育和产量构成因素的影响(简报)

遮荫使秧苗瘦长、干物质减少。在正常光照下比叶重小(叶子薄)的品种,遮荫后比叶重变化较小,干物重下降也较少。遮荫对移栽后水稻生育期的影响很大。抽穗前遮荫使生育期延迟,抽穗后遮荫使生育期缩短。遮荫愈严重,减产愈多。     

西藏小麦资源在都江堰试种的表现及评价

对125份来源于西藏的小麦地方品种进行农艺性状分析和评价。结果显示,西藏小麦植株高度总体偏高,少数适中。分蘖数多数在10个以下,少数偏多。穗长、小穗数的单位长度着生的小穗数存在明显差异,存在一些密穗类型和多小穗类型。多数小麦品种穗粒数不少,但千粒重明显偏低。性状相关分析表明,随着分集数增多、穗长增长、小穗数增多,株高有增加的趋势,而株高的增加又导致了千粒重的降低。小穗数多其穗长通常比较长。中时西藏小麦资源进行了评价、利用方式进行了探讨、在都江堰与西藏表现差异的原因进行了分析。     

光周期敏感细胞质雄性不育小麦的研究

选用我们创建的Ｄ＾２型细胞质与普通小麦品种,经多年回交核置换获得的１５种异质系在,不同发育期置于武汉不同光长条件下,并春播于哈尔滨自然长日条件下,抽穗时套袋自产,进行碘染花分观察,成熟后考察自交结实率等。     

对河南省玉米高产栽培技术探讨

玉米是主要粮食作物之一,具有生育期短、适应性广、抗逆性强、成本低、产量高而稳定等特点,属于禾本科光合作物,并且它在农业生产中占有重要地位。其主要发育期分为播种、出苗、七叶、拔节、抽穗、开花、吐穗、灌浆、成熟等生育期。本文对玉米高产栽培技术、栽培气温条件以及影响玉米优质高产的灾害因素进行了分析探讨。     

西藏小麦品种和引进品种在拉萨种植的品质比较

为了给西藏优质小麦生产的品种利用提供依据 ,1998～ 2 0 0 0年 ,用 7个西藏春小麦品种和 4个引进品种在拉萨进行了 3年春播试验 ;1998～ 2 0 0 1年 ,用 2个西藏冬小麦品种和 3个引进品种进行了 3年秋播试验。结果表明 ,西藏品种的蛋白质含量、湿面筋含量、沉降值明显低于引进品种。西藏品种属于弱筋小麦品种。西藏优质专用小麦生产中的品种利用途径是 :加强中筋小麦的生态育种 ;引进内地强筋小麦品种     

小麦形成大穗的生态学基础

研究了不同光、温条件下３个小麦品种的生育特征、幼穗分化、幼穗生长和穗部性状,探讨了促进穗大粒多、提高小麦单产的可行途径．结果表明,因播种期的不同而导致的小麦生长期间光、温条件的不同,使之各生育期出现的时间及其持续的天数有了较大的差异．小麦幼穗分化的历期天数多与平均气温和平均日照长度呈显著或极显著负相关．不同的积温是幼穗生长量和每穗总小穗数产生差异的重要原因．在条件适宜的麦区,可望通过引种适宜品种并适当提早播种期,以促进德大粒多、实现单产的明显提高．     

Archaeobotanical remains of hulled and naked cereals in the Iberian Peninsula

Archaeobotanical finds in Spain show differences in the representation of the different wheats and barleys. From the beginning of agriculture (around 5000 B.C.) onwards, all wheats and barleys can be found at the sites of the eastern Peninsula. But in later periods of the early Neolithic, free-threshing wheat becomes more important in the northeast and the southeast, compared to the hulled wheats (emmer and einkorn). Nevertheless, both naked and hulled barleys can be found in similar frequencies in this period. Seed analyses in the southeast and the east of Spain show the importance of naked barley compared with hulled barley in the third millenium uncal B.C. This is not the case in the northeast, where hulled barley has a similar frequency in this period until the Iron Age, when both hulled barley and free-threshing wheat are the most important taxa. The substitution of naked barley for hulled barley in the south-east Iberian Peninsula is very significant in the period of greatest growth of the Argar culture. Free-threshing wheat can be found at a similar frequency throughout the study area, and was an important human food source together with the barleys. Hulled wheats seem to have played a secondary role as food in all periods, although they are constantly present in our samples. Nevertheless spelt wheat does not appear until the Roman period, when it is only found on the Cantabrian north coast, where it is important.     

External and internal control of patterns of feeding, growth and gonadal function in a temperate zone anuran, the toad Bufo bufo

Young toads were brought into the laboratory before hibernation in the autumn and exposed to alternating periods of low temperature and high temperature and feeding, thus simulating climatic cycles. In newly metamorphosed, non-hibernating toads, food intake was initially low and growth was stagnant, but subsequently food intake and lean growth increased strongly. Presumably, growth was initiated independently of feeding. In one-year-old, non-hibernating toads, food intake and growth declined with time, but high rates of feeding and growth were restored in the toads exposed to simulated hibernation. In both metamorphosed toads and one-year-old, hibernating toads, a period of predominant fat deposition succeeded predominant lean growth before food intake again declined to low levels. Initiation of sexual maturation in the female toads coincided with suspended growth, whereas sexual maturation in males was not correlated with changes in growth rate. In the female, but not the male toads, sexual maturation was greatly advanced under the experimental conditions, resulting in adult female sizes far below those typical of the wild population.     

Seasonal variation of egg size in the sardine, Sardino pilchardus Walb., of the Saronikos Gulf: causes and a probable explanation

The change of egg size in sardine of the Saronikos Gulf (Greece) during the course of the spawning season is examined in relation to the changing conditions of temperature and plankton biomass. It is suggested that the intraspecific variation of egg size is an ecophenotypic rather than a genetic phenomenon, arising from the disturbance of the normal ratio between growth and differentiation rates during the oocyte stage. Assuming that a positive relation between the growth rate of the mother and the growth rate of the eggs during maturation exists, environmental or endogenous factors promoting or retarding the adult growth rate will accelerate or decrease the growth rate of the eggs in relation to the rate of differentiation, resulting in smaller or bigger eggs respectively.     

梯棱羊肚菌≥0℃积温对其生长发育的影响

为研究≥0℃积温对梯棱羊肚菌Morchella importuna生长发育的影响,通过调查不同海拔种植的梯棱羊肚菌的生长发育,应用农业气象方法和统计法计算出其不同海拔≥0℃的气温积温和地温积温。结果显示,不同海拔种植的梯棱羊肚菌生育期存在差异,但其生育期≥0℃的气温积温和地温积温差异小。梯棱羊肚菌从播种到原基分化、子实体成熟、原基发育到子实体成熟≥0℃气温积温分别为(563±21)℃·d、(712±20)℃·d、(149±21)℃·d。离地表0cm、5cm、10cm不同深度≥0℃的地温积温有较大的差异,5cm深度≥0℃的地温积温可以作为其生长发育热量需求的参考,估计区间是：从播种到原基分化、子实体成熟、原基发育到子实体成熟分别为(741±36)℃·d、(915±46)℃·d、(174±23)℃·d。     

Strong presence of the high grain protein content allele of NAM-B1 in Fennoscandian wheat

Grain protein content in wheat has been shown to be affected by the NAM-B1 gene where the wildtype allele confers high levels of protein and micronutrients but can reduce yield. Two known non-functional alleles instead increase yield but lead to lower levels of protein and micronutrients. The wildtype allele in hexaploid bread wheat is so far mainly known from historical specimens and a few lines with an emmer wheat introgression. Here we report a screening for the wildtype allele in wheats of different origin. First, a worldwide core collection of 367 bread wheats with worldwide origin was screened and five accessions carrying the wildtype NAM-B1 allele were found. Several of these could be traced to a Fennoscandian origin and the wildtype allele was more frequent in spring wheat. These findings, together with the late maturation of spring wheat, suggested that the faster maturation caused by the wildtype allele might have preserved it in areas with a short growing season. Thus a second set consisting of 138 spring wheats of a northern origin was screened and as many as 33?% of the accessions had the wildtype allele, all of a Fennoscandian origin. The presence of the wildtype allele in landraces and cultivars is in agreement with the use of landraces in Fennoscandian wheat breeding. Last, 22 spelt wheats, a wheat type previously suggested to carry the wildtype allele, were screened and five wildtype accessions found. The wildtype NAM-B1 accessions found could be a suitable material for plant breeding efforts directed towards increasing the nutrient content of bread wheat.     

Fish age at maturation is influenced by temperature independently of growth

Age and size at maturation are important correlates of fitness in many organisms and understanding how these are influenced by environmental conditions is therefore required to predict populations’ responses to environmental changes. In ectotherms, growth and maturation are closely linked to temperature, but nonetheless it is often unclear how temperature-induced variation in growth and temperature per se translate to the process of maturation. Here, we test this explicitly with a common garden experiment using nine-spined sticklebacks (Pungitius pungitius). We reared fish in 14 and 17°C and recorded high resolution growth trajectories and the timing of maturation on an individual basis. To characterize the growth of each individual, we fitted a von Bertalanffy growth curve to each measured growth trajectory, so that the three parameters of the curve provided a summary of an individual’s growth. Temperature treatments induced changes in both the growth parameters and the age at maturation. In females, changes in the age of maturation were encompassed by variations in growth, whereas in males there was a temperature-related shift in the age at maturation that was unrelated to growth. Our experiment demonstrates that temperature can affect maturation directly, and not only through temperature-induced changes in growth. Therefore, one cannot predict, on the basis of growth only, how changes in temperature might alter age and size at maturation and the subsequent reproduction.     

Expression of high zinc efficiency of Aegilops tauschii and Triticum monococcum in synthetic hexaploid wheats

The effect of varied zinc (Zn) supply on shoot and root dry matter production, severity of Zn deficiency symptoms and Zn tissue concentrations was studied in two Triticum turgidum (BBAA) genotypes and three synthetic hexaploid wheat genotypes by growing plants in a Zn-deficient calcareous soil under greenhouse conditions with (+Zn=5 mg kg^-1 soil) and without (−Zn) Zn supply. Two synthetic wheats (BBAADD) were derived from two different Aegilops tauschii (DD) accessions using same Triticum turgidum (BBAA), while one synthetic wheat (BBAAAA) was derived from Triticum turgidum (BBAA) and Triticum monococcum (AA). Visible symptoms of Zn deficiency, such as occurrence of necrotic patches on leaves and reduction in shoot elongation developed more rapidly and severely in tetraploid wheats than in synthetic hexaploid wheats. Correspondingly, decreases in shoot and root dry matter production due to Zn deficiency were higher in tetraploid wheats than in synthetic hexaploid wheats. Transfer of the DD genome from Aegilops tauschii or the AA genome from Triticum monococcum to tetraploid wheat greatly improved root and particularly shoot growth under Zn-deficient, but not under Zn-sufficient conditions. Better growth and lesser Zn deficiency symptoms in synthetic hexaploid wheats than in tetraploid wheats were not accompanied by increases in Zn concentration per unit dry weight, but related more to the total amount of Zn per shoot, especially in the case of synthetic wheats derived from Aegilops tauschii. This result indicates higher Zn uptake capacity of synthetic wheats. The results demonstrated that the genes for high Zn efficiency from Aegilops tauschii (DD) and Triticum monococcum (AA) are expressed in the synthetic hexaploid wheats. These wheat relatives can be used as valuable sources of genes for improvement of Zn efficiency in wheat. This revised version was published online in June 2006 with corrections to the Cover Date.     

Changes in reproductive strategy in the ruffe during a period of establishment in a new habitat

The pattern of maturation, body size and fecundity was examined in a population of ruffe ( Gymnocephalus cernuus L.) three times during a period of rapid growth, and eventual stabilization, following its introduction to a new habitat. When the ruffe were less common, maturing ruffe were relatively large and immature ruffe relatively small, compared with when the ruffe were abundant. Intermediate ruffe population size showed a maturation pattern intermediate between these two extremes. It is suggested that this pattern of maturation is a response of the ruffe population to changing growth opportunity induced by changing intraspecific competition. This fluctuating maturation pattern is interpreted in terms of a threshold-dependent maturation trigger, operating on the rate of accumulation of energy and a trade-off between somatic growth and gonad development. When the ruffe population was large, high intraspecific competition resulted in low opportunity for growth; only fish with the highest rate of food acquisition were able to mature in a given year–the investment in gonadal tissue reducing somatic growth. When the ruffe population was low, the high rate of energy acquisition in the population resulted in the triggering of maturation, even at small size, only the very smallest fish remaining immature. High growth opportunity allowed maturing fish to develop gonad and maintain somatic growth. The pattern of size related fecundity also changed over the three periods. When growth opportunity was low, size related fecundity was greater than when opportunity for growth was high. This suggests that maturing females faced with poor growth conditions compensated by increasing egg number for a given body size either by decreasing egg size or by increasing total investment in ovarian tissue.     

Partial antibiosis to Rhopalosiphum padi in wheat and some phytochemical correlations

The fecundity of the aphid Rhopalosiphum padi during the first ten days of reproduction was measured on five wheats at three growth stages. The wheats were of UK and Iranian origin, but also involved both spring and winter wheats as well as hexaploid and tetraploid types. Aphids which had already been reared on the respective variety for at least one generation were transferred to the experimental plants. The tetraploid Emmer showed some resistance in comparison with the hexaploid UK varieties at later growth stages, whereas the Iranian variety Moghan 2 appeared relatively resistant only at the tillering stage. The other Iranian variety, Ommid, was resistant at all growth stages, and appears to be the most resistant hexaploid wheat variety to R. padi so far identified. Correlations of aphid fecundity with plant chemistry were attempted with total phenolic compounds, hydroxamic acids and amino acids. All three of these chemical groups have previously been reported as correlated with plant resistance to cereal aphids. Even just for the results at the tillering stage, no correlation could be found for phenolics or hydroxamic acids, but a multiple regression based on the levels of alanine, histidine and threonine accounted for over 95% of the variation in aphid fecundity at all 15 data points (5 wheats × 3 growth stages). No cause or effect relationship is necessarily implied.     

Specific growth rate and proximate body composition of Atlantic cod (Gadus morhua L.)

The effect of growth rate and maturation on the proximate composition and energy content of Atlantic cod, Gadus morhua L., was investigated over 10 months for each of two consecutive years, 1978–1980 at 5 and 8 °C. Relative energy and lipid content of whole cod increased with specific growth rate for all three sampling periods (November, January, March), each at 5 and 8 °C. Relative water content decreased with specific growth rate and temperature, and was lower in March than in January and November. Relative protein content was positively correlated with specific growth rate, but to a lesser degree than with temperature and age. Relative ash content was negatively correlated with specific growth rate. The effect of season and temperature on the proximate content of gonad, liver, muscle, and carcass was also determined. The major energy and lipid source in cod was the liver. Energy, lipid, and water were highly correlated to each other, and regressions are provided to allow for their prediction, given one of the components. Energy budgets for cod at 5 and 8 °C are calculated and the effect of increased ration size on the budget is estimated. The prediction of short-term specific growth rates of cod from the proximate composition is proposed. The proximate composition of cod is affected by growth rate and thus feeding level, and in turn directly affects behaviour. The relative proximate content of maturing and immature 3-yr-old cod was not found to be significantly different. Keywords: specific growth rate; proximate; bioenergetics; Atlantic cod; energy budget; temperature; season