The influence of flowering time genes on environmental adaptability in European wheats

Summary In order to obtain high levels of environmental adaptability in wheat varieties it is essential they flower at times appropriate to particular environmental conditions. The influence of three distinct genetic systems that together determine time of flowering is reviewed here.Vernalization genes are seen to be particularly important to winter wheats for their direct or indirect effects on winter hardiness. Vernalization genes play a minor role in determining flowering time in autumn sown winter wheats but insensitivity is essential if spring sown wheats are to flower.Day length sensitive photoperiod genes play a major role in determining flowering time and adaptability of autumn sown wheats. Insensitivity can promote yield advantages of over 35% in Southern European environments. 15% in Central Europe and offers benefits even in the UK. At present only a single allele of Ppd1 appears to have been introduced into commercial European wheat varieties. The merits of alternative Ppd1 alleles or different loci are discussed.The influence of earliness per se genes that determine flowering time independently of environmental stimuli is less well documented than the effect of photoperiod and vernalization genes. It is likely that genes on chromosomes belonging to groups 2, 3, 4, 6 and 7 may act to modify flowering time independently of environmental stimuli probably by determining numbers of vegetative and floral primordia being initiated or the rate of initiation of the primordia. Earliness per se genes appear to be widespread in European wheats and play a significant role in determining the exact time plants flower.     

The use of systems analysis and modelling of growth and development in potato ideotyping under conditions affecting yields

Annual crops are usually only grown during part of the year when environmental conditions are favourable. The factors that limit the length of the available growing season for a crop are discussed from the points of view of meteorology, crop physiology and crop management. Crop yields that may be expected depend on the length of the growing season, how well the available season is used by a growing crop and on environmental factors that define (e.g. temperature, daylength and solar radiation), limit (e.g. the availability of water and nitrogen) or reduce (e.g. pests and diseases) yields. Designing genotypes for such environments requires quantitative knowledge of the influence of environmental factors on the length of the season and on dry matter accumulation and partitioning. This approach is discussed and as example the potato crop is used grown under various climatic conditions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of Climatic Factors Prevailing Prior to Flowering or Subsequent to Boll Setting on Flower and Boll Production and Retention of Cotton in Egypt

This study was conducted to investigate the nature of the effects of climatic factors prevailing prior to flowering or subsequent to boll setting on flower and boll production and retention in Egyptian cotton (Gossypium barbadense L.). Two uniform field trials, using the cotton cv. Giza 75, were carried out in 1992 and 1993 at the Agricultural Research Centre, Giza, Egypt. Randomly chosen plants were used to record daily numbers of flowers and bolls during the production stage (68 days in the first season and 62 days in the second season). The daily records of the climatic factors (air temperature, temperature magnitude, evaporation, surface soil temperature, sunshine duration and humidity) were recorded during the entire period of production and the 15 days preceding or succeeding flower opening. The effects of climatic factors on flower and boll production were quantified in non‐limiting management techniques. Relationships in the form of simple and multiple correlations were computed between climatic factors and flower and boll production and retention. The data indicate that evaporation, minimum humidity and sunshine duration were the most effective climatic factors during preceding and succeeding periods on fruit production and retention. The relationship between climatic factors preceding flowering and cotton production generally exceeded the relationship between the factors during the entire and latter periods of production stage. The result was a negative correlation between either evaporation or sunshine duration with flower and boll formation. In addition, a positive correlation was evident between minimum humidity and flower and boll production. The data indicate that low evaporation rate, reduced sunshine duration and high humidity would enhance flower and boll formation. Accordingly, the deleterious effects of climatic factors on cotton production could be minimized through applying appropriate production practices, which would control and adjust the impact of these factors, and this could lead to an important improvement in cotton yield in Egypt.     

Transgenic sugar beet tolerant to glyphosate

Phenology (i.e. the influence of environment on ontogeny) is the most important single factor influencing crop adaptation. The timing of flowering is particularly important since it largely determines when annual cereal, pulse and oilseed crops will subsequently be ripe for harvest. Two environmental factors are of overriding importance in the induction of flowering – photoperiod (daylength) and temperature. In seeking to predict times from sowing to flowering, f, it has proved profitable to analyse photothermal responses in terms of the rate of progress from sowing to flowering, 1/f. This paper summarises the advantages of a model based on rates rather than the traditional approach based on f. Over a wide range of photothermal regimes, the model involves just six coefficients, all of which (and their derivatives) have clearly defined biological meaning. Of paramount importance too is that the coefficients are not affected by the environment; they are genetic characters which determine phenotypic responses to the environment in a quantitative and predictable way.     

稳定性碳同位素在揭示环境变化中的应用

植物组织中的稳定性碳同位素组成（d13C）整合记录了气候因子和影响植物碳同化以及气孔导度的生理因子的相关信息。应用稳定碳同位素技术可以揭示环境变化中的一些相关信息。本文回顾了不同的环境因子和植物d13C的关系,以及这些关系在气候变化研究中的应用,同时进一步讨论了这项技术在重建历史气候和预测未来气候变化中的作用。     

Effect of environmental variables on performance of Jerusalem artichoke (<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L.) cultivars in a long term trial: a statistical approach

Tuber yield, together with tuber number and size are the basic agronomic and breeding traits in Jerusalem artichoke and can be significantly affected by environmental factors. We report the results of a long term trial on the performance of 20 Jerusalem artichoke cultivars. The random model for means with restricted maximum likelihood (REML) procedure was used to estimate the overall effects of the genotype, environment and genotype by environment interaction on traits. The partial least square regression (PLSR) model was used for modeling genotype by environment interaction variance components with a set of available correlated environmental variables. The REML variance component estimates model revealed that tuber number and yield are more dependent on GE interaction which allowed identification of best genotypes for specific environments. The PLSR model revealed that the most important climatic variables for optimal emergence, canopy development, high tuber number and yield are adequate soil and air temperatures in April. For larger tuber mass, precipitation variables and even distribution of rainfall were the most important factor, together with soil and air temperature in June when tuber growth is initiated. The knowledge obtained in this study is valuable for the identification and understanding of key environmental factors that contribute to the performance of Jerusalem artichoke.     

Seasonal changes in the incidence of apomixis of diploid,triploid, and tetraploid plants of Paspalum cromyorrhizon

Summary Changes in incidence of apomixis were determined at different intervals of the flowering period in a highly sexual diploid cytotype of Paspalum cromyorrhizon Trin., a natural tetraploid cytotype of the same species, and in the triploid and tetraploid intraspecific hybrids that were produced by pollinating the 2x cytotype with pollen of the tetraploid. Reproductive behaviour was determined from observations of embryo sacs in mature ovules. Gametophytic apomixis in this species in characterized by aposporous embryo sacs which differ from normal sacs by their number, orientation inside the ovule, their dimensions and shape, and the absence of antipodal cells.The potential for apomictic reproduction increased in relation to the ploidy level, suggesting a gene dosage effect in the incidence of apomixis. In the three ploidy levels, the highest incidence of apomixis was observed when the plants reached the maximum number of flowering heads. These findings suggest that the same environmental conditions that favour flowering should also be responsible for increasing the incidence of apomixis. An additional experiment under controlled conditions indicated that the light regime should be one of the factors that govern the amount of apomictic reproduction. Thus, polyploidy and apomixis should be of special significance in the dispersion and evolution of this grass species. The 4x facultative apomictic cytotype is far more frequent in nature than the highly sexual 2x. Moreover, most of the seeds produced in a flowering season should arise asexually. So, apomixis rapidly increases the number of plants bearing the successful maternal genotype, and sexual reproduction becomes important in adverse environmental conditions.     

桂花花期气象预报研究

为了更准确地提供桂花开花期的预报,利用桂林市近15年的始花期观测资料,普查分析气象原因,挑选气象因子,用统计分析方法,建立预报模式。结果表明,温度、湿度、日照、降水对桂花开花期有明显影响;影响桂花花期的原因比较复杂,在实际进行花期预报时,根据时间提前的长短,又可以分为长期预报和短期预报,长期预报又为气候预测,只是花期偏早或偏迟的趋势预测,短期预报则是临近开花前1周的预报。长期预报模式和短期预报模式在2013年的业务应用中取得了较好的效果。     

高粱产量预测模型研究——以屯留区为例

研究屯留区高粱产量对气候环境条件的响应,探讨气候因子与高粱产量的关系,为屯留区高粱高效生产提供理论和技术参考。首先,通过粒子群优化算法对指数平滑系数进行优化,进而运用三次指数平滑法将高粱产量分解成趋势产量与气象产量2部分。其次,采用灰色绝对关联法得出对高粱气象产量影响较大的气候因子。最后,对屯留区2004—2017年高粱实际产量进行多元线性回归模型拟合,并利用2018年高粱实际产量对其模型进行验证。结果表明：影响高粱产量的主要气候因子有5月降雨量、5月光照时长、6月平均相对湿度、6月降雨量、7月降雨量、7月光照时长、8月降水量、9月光照时长。2018年高粱产量验证多元线性回归模型的精确度为81.06%,表明该模型能相对准确地拟合屯留区的高粱产量,可为高粱产量的准确预测提供了方法借鉴。     

密度对棉花株间小气候、农艺性状及产量的影响

为掌握棉花群体结构中的小气候环境状况,确定棉花不同密度对产量的影响,设计6个不同密度测定农艺性状,选择棉花郁闭度最大的开花盛期,测定不同棉花密度群体田间小气候要素。结果表明,密度不同棉花的农业性状发生很大变化,群体间光、温、湿度等气候因子有较大的改变。随着密度的增加,棉花株高、茎粗、叶片数、果枝数、蕾数、铃数、铃重与株间梯度温度差呈显著负相关,而与透光率呈正相关;最佳密度群体株间梯度温度差应0.3~0.4℃;棉株间地面透光率应在5.5%以上。密度22.5万株/hm²产量表现最佳,其次是27.0万株/hm²,再其次是18.0万株/hm²。在当前栽培管理水平下,北疆早熟棉花品种的种植密度以20万~25万株/hm²为宜。     

春石斛生物学特性及栽培技术研究进展

春石斛（Dendrobium nobile）为兰科（Orchidaceae）石斛属（Dendrobium）植物,因其花姿优雅、花色艳丽、花期长等特点而深受消费者青睐。笔者综述春石斛的生物学特性、繁殖技术、环境调控、花期调控等几方面的研究进展,同时对研究中存在的花期调控、繁殖技术和栽培管理模式等问题进行了分析。认为如何解决花期调控,提高开花的品质是春石斛产业研究的当务之急,并提出开展利用激素进行花期调控研究,选育需求低温量少、春化容易的早花新品种,将是春石斛研究的未来方向。     

Association between growth habit and persistence in red clover

Summary Three double-cut red clover (Trifolium pratense L.) varieties: Prosper I, Florex, and Tristan each with two different seedlots were space-planted in a field. The total number of plants established for each seedlot was about 900. In the seedling year, plants were classified into five growth types according to rosette development and flower production. In the fall of the third year 14% of the rosette-forming, non-flowering Type 1 plants were alive; 8–11% of the intermediate types survived; and only 2% of the nonrosette-forming, profusely flowering Type 5 plants remained growing. The non-flowering class (Types 1 and 2) persisted better than the flowering class (Types 3, 4, and 5). This difference in persistence was similar for all three varieties regardless of seed source. The two flowering classes, in the production years, had the same proportion of the most vigorous plants. The most vigorous plants of the non-flowering class had the same frequency distribution of seed yield as those of the non-flowering class. In conclusion, the flowering response can be used as a selection criterion for persistent plants; and plants not flowering in the seedling year can attain a forage and seed yield as high as flowering plants in the production years. Screening for non-flowering plants can be carried out at the seedling stage in the greenhouse before seedlings are transplanted to the field.Contribution No. 520, from the Charlottetown Research Station, Agriculture Canada, Prince Edward Island, Canada.     

Bayesian threshold analysis of breeding values,genetic correlation and heritability of flowering intensity in <Emphasis Type="Italic">Eucalyptus cladocalyx</Emphasis> under arid conditions

In the dry regions of Chile, prolific flowering from forest plantation is particularly advantageous for honey production, in order to supplement the erratic flowering in native plants. Eucalyptus cladocalyx is a species suitable for areas with low water availability and their flowers provide a reliable source for the production of honey. The aim of this study was to examine the heritability of flowering intensity in 49 open-pollinated families of E. cladocalyx in southern Atacama Desert, Chile, with the view to the selection for prolific flowering, but with minimal impact on precocious flowering. The Bayesian variance component estimation model was assumed using the Gibbs sampling algorithm. Threshold models were fitted to flowering data (bi-character model). Flowering intensity was found to be highly heritable (posterior mean: h ² = 0.48; and credible interval: 0.41–0.56). The posterior mean of the genetic correlation between flowering precocity and intensity was positive (r = 0.45) and according to the credible interval (0.341–0.542), it was significantly different from zero, indicating that selection on breeding values of early flowering at age three, would have significant and positive impact on flowering intensity 5 years later (or in 8-year-old trees). These results are important for the start of a small-scale breeding program for the species in southern Atacama Desert. The genetic variability found in these breeding populations may be used for breeding purposes in regions where arid environmental conditions are limiting to the establishment of eucalypts trees.     

Methods for evaluation of soybean chilling tolerance at the reproductive stage under artificial climatic conditions

Several evaluation methods for soybean chilling tolerance at the reproductive stage were examined under artificial climatic conditions. Comparisons were made on plants in control and treated plots using three cultivars differing in the level of chilling tolerance. In all methods, plants were grown at 22/17°C (day/night) until first flowering, and then transferred to growth chambers at 24/17°C for control and 15/15°C for chilling treatment, respectively. A method, in which plants were grown at 20/16°C after 4 weeks of the different temperature treatments, proved comparable to the conventional one, in which chilling tolerance at the flowering stage is evaluated using natural and artificial conditions. Another method, in which the plants in chilling treatment plots were grown at 15°C until maturity, also proved usable to evaluate genotypic differences in chilling tolerance independently of maturity time.     

Heading behaviour in Japan of Turkish populations of cocksfoot,Dactylis glomerata L.

Summary Ninety-nine populations of cocksfoot collected throughout Turkey were examined for heading behaviour at Sapporo, Japan. In some populations, all the plants produced heads in the year of sowing or in the aftermath of the next year. Much of the Turkish populations, even from the mountainous regions with severe winters, is also distinct in heading behaviour in autumn from the north European types, which fail to head in the year of sowing. This behaviour is related to winter temperatures of the place of origin, with the milder winter tending to result in a higher heading rate. Date of heading is also influenced by the climatic factors of the habitat, especially by the length of the growing period between winter and summer dormancies. Turkish populations provided useful material for the study of flowering habit.     

油用牡丹花期预报

根据菏泽市2008—2019年油用牡丹花期观测资料及相应气象要素,利用滑动平均、相关分析及逐步回归等数理统计方法,分析了影响菏泽市油用牡丹始花期早晚的主要气象因子。结果表明：温度条件是影响油用牡丹始花期主要的气象因子之一,并与花期呈显著负相关;日照、降水及日较差等气象条件与油用牡丹始花期相关均不显著。选取2008—2018年对牡丹花期影响较大的气象因子,采用逐步回归方法,建立了油用牡丹始花期预报模型,可分别于3月21日、4月1日发布花期预报。模型历史回代（允许误差均在±1天）,并对2019、2020年进行试报,准确率均为100%,拟合程度较为理想,试报效果较好,满足气象服务需求。     

皖南烟叶大田生育期气候条件动态评价研究

为开发能较好评价皖南烟叶大田期年度气候条件的方法,反映光温水气候因子对皖南地区烟叶生长过程的综合影响,根据烟叶的生长规律和气候条件,构建光温水气候影响函数,用主成分分析(PCA)分析演变规律,并用PCA方法确定光温水在烟叶各发育阶段的影响权重,构建烟叶气候综合影响函数。以2012年资料为实例,先分旬计算温度、降水和日照时数单因子气候影响函数和综合气候影响函数,绘制旬气候函数影响历史演变图,再计算气候要素距平,最后通过归纳汇总,分析皖南烟叶大田期气候条件对烟叶生长的影响。用气候影响函数绘制气候影响效果历史演变图,能直观地反映烟叶生育进程中光温水条件的变化对烟叶生长的影响效果,与评价常用的气候距平法结合,可分析出气候条件对烟叶生长和产量质量影响的过程、程度和成因,具有客观定量的优点,又由于它以气候平均值为基础,便于进行年际和不同地域差异的比较,评价用语标准、通俗,方便服务利用,对开展烟草长势趋势预测和评估、总结烟叶生产管理经验和促进烟叶气候资源合理利用会有帮助,同时,本研究所提供的方法也是一种能提高识别气候变化主因准确度的方法。     

Differential Expression Pattern Of MADS Box Genes in Floral Whorls of Garcinia indica

Journal of Crop Science and Biotechnology - Flower formation is one of the main developmental stages in the life cycle of flowering plants that can be used as a model system to elucidate the...     

伞形科根茎类药用植物早期抽薹的研究进展

通过简述伞形科根茎类药用植物发生早期抽薹现象的过程,明确伞形科根茎类药用植物发生早期抽薹的原因和影响因素,推测早期抽薹与某些调控开花的基因表达能力有关。另外,认为植物体内激素合成在一定程度上能够调节早期抽薹现象的发生。植物内源激素的合成、代谢、信号传导等过程特定基因发生差异性表达导致植物发生早期抽薹现象。提出可以从植物内源激素分子基因层面及激素作用机理出发,通过改变伞形科根茎类药用植物生长条件或施加外源性激素等人工手段有效抑制早薹率,这将对提高药用产量和品质有重要意义。     

Identification and sequence characterisation of molecular markers polymorphic between male kiwifruit (Actinidiachinensis var. deliciosa (A. Chev.) A. Chev.) accessions exhibiting different flowering time

Fruit set in kiwifruit is strongly dependent on pollination, which is limited by the lack of efficient male pollen donors, among other factors. We searched for molecular markers that could be polymorphic in relation to flowering time in order to classify male kiwifruit plants to discard those that are not likely to perform as efficient pollen donors. Random amplified polymorphic DNA (RAPD) and modified amplified fragment length polymorphism (AFLP) markers were generated using 41 male kiwifruit plants in two flowering groups, early- and late-flowering males (with respect to the female cultivar ‘Hayward’). One RAPD and nine modified-AFLP markers polymorphic between male plants exhibiting different flowering time were identified, sequenced and analysed in databases. Unweighted pair group method with arithmetic average (UPGMA) clustering and multidimensional scaling showed that these markers could be used to classify the male plants into flowering groups. Analysis of molecular variance (AMOVA) agreed with this classification, showing that most of the genetic variation is found between flowering groups. Sequence analysis based on a database search revealed that the polymorphism PolM contains a 7-nucleotide long element involved in the repression of the phytochrome A gene, that Pol4 is a partial sequence of a phytochrome B gene, and that sequences Pol3, Pol5, Pol7, and Pol9 show high identity with ESTs from kiwifruit buds treated with hydrogen cyanamide. Clustering analysis supported the previous classification of males into flowering groups, making it feasible to predict male plants’ flowering times with respect to the cultivar ‘Hayward’ based upon these molecular markers.