光周期对大豆杂交F2群体变异的影响及广适应性种质选育的研究

采用不同光照反应类型的大豆品种进行杂交，对其Ｆ２代进行光照诱导，研究短光照对大豆杂交Ｆ２代谢体变异的影响，并通过杂交育种等手段选育光钝感大豆新种质。试验结果表明，不同类型的杂交组合在Ｆ２代进行短光照处理后，其群体的变异明显不同，双亲均为不敏感的组合Ｃ１，基Ｖｅ－Ｒ１的天数、株高和主茎节数处理与对照相比差异不大，而亲本之一为光照敏感材料的组合Ｃ２和Ｃ３却表现出差异很大；选育出哈９１－７１１６，哈９２     

两种光周期对青梗菜生物产量的影响

将青梗菜分别栽培在长日照和短日照条件下,观测其叶片数、鲜重、干重和氮素运转效率的变化。结果表明,长日照处理下的青梗菜生长速度、生物产量明显高于短日照处理。     

切花菊"神马"花期调控的研究

研究了切花菊"神马"花期调控的基本方法和每个环节的关键技术措施.通过人为创造最佳环境,可以打破一年只开一次花的自然属性,按需开放,实现周年生产,为实现可观的经济收入和其他花卉生产提供参考.     

红麻光周期钝感材料的鉴定与遗传分析

开花期是影响红麻纤维产量和品质的关键因素之一。本文通过分期播种调查6份新引育的红麻品系的光周期反应,结果表明其光周期反应敏感度变化在36.0%~56.2%之间,其中赞引1号最低(36.0%),福红952B最高(56.2%)。将赞引1号与福红952B杂交,在自然短日照条件下对其正反交F1分析表明,开花期性状受核基因控制,不存在细胞质效应,光周期敏感对光周期钝感为显性。在自然短日照条件下对该组合的4个群体(P₁、P₂、F₁和F₂)联合分析发现,赞引1号的光周期钝感特性受1对加性-显性主基因和加性-显性-上位性多基因模型(D-1)控制,主效基因的加性效应值为8.2 d,遗传率为80.2%。该研究有助于红麻光周期钝感种质改良及主效基因定位。     

以光周期处理与分期播种试验综合鉴定大豆品种的光温反应

设置短日照(12 h)和长日照(16 h)两种光周期处理,并以春播模拟低温、夏播模拟高温条件,形成长日+低温、长日+高温、短日+低温、短日+高温4种光温组合。2007年对近年育成的10个北方春大豆[Glycine max (L.) Merr.]品种(系)和18个黄淮海夏大豆品种(系)进行了光温反应特性鉴定。2008年对50份材料进行了光周期反应鉴定。结果表明,不论在低温(春播)还是高温(夏播)条件下,短日照均加快大豆的发育进程,导致开花提前;不论在长日照还是短日照条件下,高温均减少出苗至初花的日数。光周期和温度对大豆的发育存在明显的互作,随着温度的升高,短日照促进大豆发育的效应有所加强;随着日照的缩短,高温加快发育的作用也有所增大。供试大豆品种生态类型在光周期反应敏感度(PRS)、温度反应敏感度(TRS)及光温综合反应敏感度(PTCRS)等方面均存在显著差异。北方春大豆品种的上述3个指标均小于黄淮海夏大豆品种,但前者在不同光照条件下的温度反应敏感度差值和在不同温度条件下的光周期反应敏感度差值均较后者高,说明北方春大豆品种光温互作效应较强。     

A model driven by crop water use and nitrogen supply for simulating changes in the regional yield of rain-fed lowland rice in Northeast Thailand

Climate change will have significant impacts on the rain-fed rice production ecosystem, and particularly on the ecosystem’s hydrology and water resources. Under rain-fed lowland conditions, substantial variations among fields in grain yield are commonly observed, but a method that can account for field-scale yield variability to produce regional-scale yield estimates is lacking, thereby limiting our ability to predict future rice production under changing climate and variable water resources. In this study, we developed a model for estimating regional yields of rain-fed lowland rice in Northeast Thailand, by combining a simple crop model with a crop calendar model. The crop model incorporates the effects of two important resources (water and nitrogen) on crop growth. The biomass accumulation is driven by water use, whereas the nitrogen supply determines canopy development and thereby constrains crop water use. Accounting for the wide range of planting dates and the strong photoperiod-sensitive characteristics of rice varieties through the calendar model is an essential component in determining regional yield estimates. The present model does not account for the effects of mid-season drought or flooding, but was nonetheless able to explain the spatial and temporal yield variations at the province level for the past 25 years. Thus, it can be used as a prototype for simulating regional yields of rain-fed lowland rice.     

Modeling the dependence of the crop calendar for rain-fed rice on precipitation in Northeast Thailand

Rain-fed lowlands are major agricultural ecosystems used for rice production in Northeast Thailand. Developing a tool to assess the effects of variable water conditions on the regional scale yield is also important to predict the effects of climate change on food supply. To estimate regional yields, we need a simple but accurate measure of the crop calendar (i.e., the distribution of planting dates), which has a strong influence on grain yield. In this article, we modeled the dependence of the crop calendar on rainfall patterns based on a survey of the region’s farmers as a part of an effort to provide a stronger basis for regional yield estimates. Our survey, conducted in 11 provinces for 2 years, confirmed the existence of large windows for sowing and transplanting versus narrow windows for heading and harvesting for rain-fed lowland rice culture in all the provinces. Variable water, soil, and toposequential conditions in the paddy fields were responsible for the large sowing and transplanting windows, whereas the use of photoperiod-sensitive varieties explained the narrow windows for heading and harvesting. The crop calendar was well expressed as a function of cumulative precipitation from June onward. When the crop calendar model was combined with a simple phenology-based model that uses growing degree-days adjusted by a day-length factor, we could estimate the rice crop calendar under rain-fed lowland conditions with acceptable accuracy. The model described in this article will be combined with a crop growth model to improve regional yield estimates for rain-fed lowland rice.     

温光条件对胞质不育系V太911289a雄性育性影响的初步研究

研究自然播种和人工控制光温条件下V型胞质不育系的雄性稳定性,以期为选育新的光温敏胞质不育系提供试验依据。     

燕麦光周期不敏感基因的分子标记

为了寻找燕麦光周期不敏感基因的分子标记,本研究采用SSR及AFLP标记对来自加拿大和中国的22份燕麦材料进行了DNA指纹分析及光周期不敏感基因的分子标记研究。结果表明,所选6对燕麦SSR引物中有3对扩增出多态性高的条带,通过带型分析可以将所研究的多数燕麦品种区分开,所选的10对大麦SSR引物和4对小麦SSR引物在22个燕麦品种中多态性不高,不能将不同燕麦品种区分开来。同时利用AFLP标记对其中5个不同熟期的燕麦材料进行了分析,64对AFLP引物组合经选扩共获得18 240个条带,平均57条/引物组合。统计分析AFLP图谱,获得品种特异条带20条,可将各燕麦品种区分开。此外获得光周期不敏感燕麦品种特异条带2条,可作为燕麦光周期不敏感基因的相关分子标记。     

Distribution of the photoperiod insensitive <Emphasis Type="Italic">Ppd-D1a</Emphasis> allele in Chinese wheat cultivars

Photoperiod response is of great importance for optimal adaptation of bread wheat cultivars to specific environments, and variation is commonly associated with allelic differences at the Ppd-D1 locus on chromosome 2D. A total of 926 Chinese wheat landraces and improved cultivars collected from nine wheat growing zones were tested for their genotypes at the Ppd-D1 locus using allele-specific markers. The average frequency of the photoperiod-insensitive Ppd-D1a allele was 66.0%, with the frequencies of 38.6 and 90.6% in landraces and improved cultivars, respectively. However, the Ppd-D1a allele was present in all improved cultivars released after 1970 except for spring wheats in high latitude northwestern China, and winter wheats in Gansu and Xinjiang. The presence of the Ppd-D1a allele in landraces and improved cultivars increased gradually from north to south, illustrating the relationship between photoperiod response and environment. Ppd-D1a in Chinese wheats is derived from three sources, Japanese landrace Akagomughi and Chinese landraces Mazhamai and Youzimai. The current information is important for understanding the broad adaptation of improved Chinese wheat cultivars. F. P. Yang and X. K. Zhang contributed equally to this work.