雨养和灌溉条件下小麦叶片光合特性的比较

摘要：在雨养和灌溉条件下,以小麦品种“青麦6号”为研究对象,对小麦灌浆期旗叶的光合速率、蒸腾速率、气孔导度、水分利用率对光强的响应及各种光合特性指标间相关性进行研究。结果表明：在雨养和灌溉两种处理下光合速率、气孔导度都随光强的增大而增大,都可以用Michaelis-Menten方程模拟;在高光强下灌溉处理的光合速率、气孔导度比雨养处理的高。灌溉处理的蒸腾速率比雨养处理的高,但其水分利用率却低于雨养处理。光合速率与蒸腾速率因气体交换的同步性而具有明显的线性关系,但水分亏缺对蒸腾速率的影响相对于对光合速率的影响更直接、更强烈。     

Quantifying growth and development of bulb turnips

Bulb brassicas are used as supplementary feed in intensive pastures systems. However, there is a lack of quantitative data to define their growth and development. This has limited the creation and use of prediction models and decision support systems. Thus a field experiment measured growth and development of ‘Barkant’ and ‘Green Globe’ turnips sown on five dates from November 2008 to March 2009. In a second field experiment ‘Green Globe’ turnips were sown on four dates from December 2009 to March 2010, under two ground cover treatments that changed mean soil temperature by ∼2 °C. Bulb initiation was defined botanically as when the hypocotyl was 10 mm thick, at 360 °Cd (±13.0) for ‘Barkant’ and 420 °Cd (±13.7) (T_b = 3.6 °C) for ‘Green Globe’. However, the bulb participation in dry matter production occurs after an 18 mm hypocotyl thickness, which occurred at ∼500 °Cd for both turnip cultivars. A single base parameter of 0.995 described the exponential decline of the leaf:bulb ratio. Relationships also described how leaf production and total leaf area expansion changed up until bulb initiation. Radiation use efficiency (RUE) ranged from 1.13 to 1.33 g DM/MJ total. A constant rate of total leaf area expansion (0.015 m²/m²/°Cd) was obtained up to LAI_c for ‘Green Globe’ turnips. A third pot experiment confirmed the thermal time requirement to bulb initiation based on direct assessment of the hypocotyl thickening of ‘Barkant’ and ‘Green Globe’ turnips. Temperature was shown as the main driver of bulb development and growth. The relationships provided could be used to improve the performance of prediction models.     

Juvenile phase and growth of apple and pear seedlings

It was investigated whether and to what extent the duration of the juvenile phase of pear and apple seedlings is related to their vegetative growth. The juvenile phase was defined as the period in years that the seedling remains vegetative; the trunk diameter served as a measure of vegetative vigour. The following observations were made:

1. 1)

   A significant negative correlation exists between the duration of the juvenile phase and the vigour of the seedling (as measured by trunk diameter).

2. 2)

   Environmental conditions with respect to weather, soil and cultural practices which promote or restrict growth, tend to shorten or lengthen the juvenile phase accordingly by their influence on the time required for the attainment of a certain minimum size which at least partly determines the attainment of the flowering condition.

3. 3)

   The weak rootstock M. IX significantly accelerated the onset of flowering of apple seedlings by about 1 1/2 years; this rootstock appears to combine a retarding effect on growth with a specific influence on flowering.

     

黄化病对葡萄生长发育的影响

[目的]为了研究黄化病对葡萄生长发育的影响。[方法]以吐鲁番主栽品种无核白和无核白鸡心为试材,通过对不同黄化程度葡萄的叶片生长量、叶绿素含量及果实产量等指标进行对比分析。[结果]黄化对葡萄植株生长、果实产量和品质造成了严重危害。随着葡萄黄化程度的加剧,两种葡萄植株的单叶重、叶长、叶宽及单叶厚等逐渐减小,且黄化株生长量较正常株明显下降。黄化植株葡萄的产量较低,两种葡萄正常园产量分别是黄化园产量的2.47倍和2.51倍,果粒大小和可溶性固形物也显著低于正常植株。采用不同方法提取叶绿素含量比较得出,利用丙酮研磨法提取两种葡萄叶绿素含量的效率均优于乙醇浸泡法。[结论]黄化病造成葡萄叶片光合代谢失调,植株生长迟缓,严重威胁着吐鲁番葡萄产业的健康发展。对黄化病的发生原因进行深入分析,并采取有效的防治措施是现在葡萄生产上比较棘手的问题。     

In vitro pollen germination and tube growth of tomato (Lycopersicon esculentum Mill.) and its relation with plant growth

Summary In vitro pollen germination at 10°C, 14°C and 22°C of four groups of two pure line tomato varieties was compared with their plant growth at 19°C D/10°C N under controlled environmental conditions. Generally, pollen germination was slow at 10°C but after 6 h the percentage of germination was similar to that at 22°C. Maximum germination was obtained at 14°C already after 4 h. The longest pollen tubes occurred at 22°C. The two varieties within each group differed significantly from each other for percentage of pollen germination. For one group, this difference was greater at 10°C than at 22°C. The varieties in two groups also differed significantly for pollen tube growth. These differences in pollen tube growth rate were greater at 22°C than at 10°C. There was no clear relationship between pollen germination, pollen tube growth and plant growth in any of the four pairs of varieties. The results are discussed with regard to the possibility of pollen selection at low temperature in order to improve the efficiency of breeding for growth at low temperature.     

Maize response to broadcast flaming at different growth stages: Effects on growth,yield and yield components

Weed management is a major constraint in organic crop production. Propane flaming could be an additional tool for weed control in organic maize (Zea mays L.) production. However, tolerance of maize to broadcast flaming must be determined first to optimize the use of propane. Field experiments were conducted at the Haskell Agricultural Laboratory of the University of Nebraska, Concord, NE in 2008 and 2009 to determine maize response to five propane doses applied at three growth stages of V2 (2-leaf), V5 (5-leaf) and V7 (7-leaf). The propane doses tested were 0, 13, 24, 44 and 85 kg ha^?1. Flaming treatments were applied utilizing a custom built research flamer mounted on the back of a four-wheeler moving at a constant speed of 6.4 km h^?1. The response of maize to propane flaming was evaluated in terms of visual crop injury (1, 7, 14 and 28 days after treatment—DAT), effects on dry matter (14 DAT), yield components (plants m^?2, ears plant^?1, kernels cob^?1 and 1000-kernel weight) and grain yield. The response of different growth stages of maize to propane doses was described by log–logistic models. Overall, maize response to broadcast flaming varied among growth stages and propane doses. In general, maize at V5 was the most tolerant stage for broadcast flaming, whereas V2 stage was the most susceptible to flaming resulting in the highest visual crop injury ratings, dry matter reductions and the largest loss of yield and its components. At 28 DAT, the maximum visual crop injury rating of 7% was estimated for flaming done at V5 stage compared to significantly higher injuries of 43% and 12% for V2 and V7 growth stages, respectively. An arbitrarily assigned 2.5% yield reduction was evident with 33, 16 and 11 kg ha^?1 of propane for V5, V2 and V7 growth stages, respectively, suggesting that maize flamed at V5 stage can tolerate higher dose of propane for the same yield reduction compared to other growth stages. Moreover, the maximum yield reductions with the highest propane dose of 85 kg ha^?1 were 3% for V5, 11% for V7 and 17% for V2 stage. Based on these results, flaming has a potential to be used effectively in organic maize production when conducted properly at V5 stage. However, there are both benefits and concerns associated with the use of flame weeding. The preservation of the soil from erosion and the protection of the surface and underground water from chemical pollution can be seen as benefits, while the concerns include higher energy use, and the release of greenhouse gasses.     

多功能高分子植物生长调节剂在干旱区玉米生产上的试验效果初报

报道了以观测记录和拍照方式研究多功能高分子植物生长调节剂对玉米生长和繁殖的影响结果，分别用玉米生长、结实和产量指标、玉米品质指标以及经济效益指标与对照比较以评定试验效果。结果显示，施用试剂有利于玉米的营养和结实生长，使玉米产量增加11.06%、品质有所改善（试验组玉米粗蛋白和粗脂肪含量有所提升），经济效益有所提高，仅仅考虑增产就净增产值607.95元/hm2。     

菌草产业成长及其多功能性探析

本文阐述了菌草技术的发展与菌草产业的成长概况;总结了菌草业多功能性的特征:我国菌草业具有食物供给、原料供给、资源节约、环境保护、就业减贫、营养保健和文化休闲等功能;提出新形势下拓展菌草业多功能性的思路：强化菌草业的食物保障功能、开发菌草业的生物质能源功能、彰显菌草业的生态保护功能。     

Geostatistical interpolation and aggregation of crop growth model outputs

Many crop growth models require daily meteorological data. Consequently, model simulations can be obtained only at a limited number of locations, i.e. at weather stations with long-term records of daily data. To estimate the potential crop production at country level, we present in this study a geostatistical approach for spatial interpolation and aggregation of crop growth model outputs. As case study, we interpolated, simulated and aggregated crop growth model outputs of sorghum and millet in West-Africa. We used crop growth model outputs to calibrate a linear regression model using environmental covariates as predictors. The spatial regression residuals were investigated for spatial correlation. The linear regression model and the spatial correlation of residuals together were used to predict theoretical crop yield at all locations using kriging with external drift. A spatial standard deviation comes along with this prediction, indicating the uncertainty of the prediction. In combination with land use data and country borders, we summed the crop yield predictions to determine an area total. With spatial stochastic simulation, we estimated the uncertainty of that total production potential as well as the spatial cumulative distribution function. We compared our results with the prevailing agro-ecological Climate Zones approach used for spatial aggregation. Linear regression could explain up to 70% of the spatial variation of the yield. In three out of four cases the regression residuals showed spatial correlation. The potential crop production per country according to the Climate Zones approach was in all countries and cases except one within the 95% prediction interval as obtained after yield aggregation. We concluded that the geostatistical approach can estimate a country’s crop production, including a quantification of uncertainty. In addition, we stress the importance of the use of geostatistics to create tools for crop modelling scientists to explore relationships between yields and spatial environmental variables and to assist policy makers with tangible results on yield gaps at multiple levels of spatial aggregation.     

Arrested growth and urban sustainability in the Asia Pacific

City managers throughout the Asia Pacific region are turning to the concept of sustainability in order to guide urban growth. This research note reviews the dominant contemporary urban and regional planning concepts promoted during the last few decades, shows how the financial crises challenged this mode of thinking and led to the adoption of sustainable urban development policies.     

棉花根系生长与叶片衰老的协调性

为探索棉花根系生长和叶片衰老之间的协调性,选用早熟性一致但衰老快慢有明显差异的棉花基因型百棉1号(叶片衰老慢)和DP99B (叶片衰老快),于2011—2012年,在田间条件下研究了其根系生长和活力、叶片衰老和产量。结果表明, 2年间百棉1号的纤维产量(皮棉及霜前皮棉)均显著高于DP99B。百棉1号的叶片光合作用或基于吸收光能的性能指数显著高于DP99B。百棉1号的根系长度密度和根系深层分布比例及根系活力(以伤流液总量和伤流液蛋白质含量表示)显著高于DP99B。2012年结果显示,DP99B根系生长比百棉1号快,并且DP99B根系长度密度及根系活力分别在8月中旬和7月下旬显著高于百棉1号,且伤流液分泌总量是百棉1号的1.7倍。棉花盛花期后,根系密度大、伤流液分泌多和叶片衰老晚具有一致性,证实棉花叶片衰老受后期根系生长和活力的调控。     

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.     

Genetic differences in growth within and between Lycopersicon species

Summary Growth analyses were carried out on 88 accessions of five Lycopersicon species. Experiments were conducted in a climate room at 19/14° C day/night temperature which was irradiated at 20 W/m² for eight hours per day. Large differences in plant weights between wild species and the cultivated tomato were observed from 44 to 84 days after sowing. The increase in plant dry weight could be described by a second order polynomial function. When compared at a standardized plant weight of one gram, the relative growth rates (RGR) of the wild and cultivated accessions ranged from 5.3 to 11.8% and 8.5 to 12.2% per day respectively, limiting the use of wild species as sources for strong growth. When expressed at plant weights of one and three g large differences in decrease of the RGR were observed within L. esculentum. The modern hybrid tomato cultivars were among the fastest growing genotypes, with a relatively slow decrease in RGR.     

Temperatures and the growth and development of wheat: a review

We start by outlining the general effects of climatic variability and temperature extremes on wheat yields in the context of extreme event effects on crop processes for climatic impacts studies. We then review literature describing the responses of wheat plants to extreme temperatures. Cardinal temperature thresholds for different phenological processes in wheat are identified and we outline the effects of temperature on rates of growth and development. Finally, we assess the implications of the above for future climatic impact studies.Our summary shows how relatively small and consistent are the standard errors of the cardinal mean temperatures for many of the processes examined. Cardinal temperatures are conservative between studies and are seemingly well-defined in wheat. Into this category we put the lethal limits for wheat, the sterility response at anthesis, the cardinal temperatures for vernalization and some of the base and optimal temperatures. Important questions for the future involve the effects of combinations of extreme events and the modelling of specific effects such as the influence of high temperatures on grain set.     

云魔花15植物学特征及生育表现

云南种植魔芋历史悠久,优越的气候条件十分适宜魔芋的生长,品种资源十分丰富.本文对云魔花15特征特性及生育表现进行评价,为下一步在云南省魔芋生产上推广提供依据.     

Inter-varietal pollen tube growth and ovule penetration in the avocado

Summary Results are presented showing number of pollen tubes in the pistil, and ovule penetrations in crosses involving the avocado varieties Edranol, Ryan, Hass, Reed, Talbot, Jalna, Fuerte, Bacon and Sharwil. Between 5% and 100% of the ovules in each cross were penetrated by a pollen tube. The female parent exerted more control than the male on numbers of tubes and ovule penetrations and the results for type A varieties were more consistent than those for type B varieties. Penetration of an ovule by two tubes was observed in all varieties except Reed and Fuerte and penetration of an ovule by three tubes was observed in the variety Edranol only. With the possible exception of the variety Bacon as female parent there was no difference between pollination with pollen from type A or B varieties.     

Heterosis in growth and photosynthetic rate in hybrids of cotton

Summary The intraspecific (Gossipium hirsutum) and interspecific (G. hirsutum x G. barbadense) F₁ hybrids of cotton were found to exhibit a high degree of heterosis in the production of fruiting branches, number of bolls (fruits), yield of seed cotton and photosynthetic rates over the parent plants. The developing bolls of the hybrids had significantly higher weights than their parents until the 20th day after anthesis. The patterns of leaf area development among interspecific hybrids differed when compared with the parent plants. The photosynthetic rates of the hybrids were comparable with those of maize and sorghum and much higher than the average rate reported so far for the cotton plant.     

Analysis of blasting gas mechanism and rock crack growth

Blasting gas effect and rock crack growth have an important influence on rock breaking.The initial pressure of blasting gas under different dynamite installation structures and gas pressure’s variation with the displacement of stemming material are analyzed, from Newton’s second law the relationship of stemming material’s length and the time that it movements in hole under blasting gas pressure effect is derived. The rock crack growth is analyzed by using BCM model,the time that crack grows from hole wall to free surface along minimal resistance line is defined as rock breaking time, let the rock breaking time equal to movement time of stemming material in the hole, the calculation model for calculating stemming material optimal length is established. The model considers two aspects, which are the stemming material movement under blasting gas pressure effect and crack growth leading to rock breaking. The theoretical value is compared with empirical value and experimental value,and theoretical value is close to empirical value and experimental value, so the theoretical model has a definite reliability and can provide theoretical guidance for blasting engineering.