试对中国粮食自给率实现95%的目标之分析

中国是世界粮食生产和消费的大国,粮食自给率水平的高低不仅仅关系到国内粮食的生产、消费乃至农业的发展方向,而且对于世界粮食市场的稳定和繁荣也有极为重要的影响。在此,在前人研究的基础上首先对中国粮食自给率现状进行了分析;进一步从粮食的需求量、供给量出发,分析了中国粮食自给率存在的隐患,最后提出了稳定粮食自给率的对策建议。     

Grain Yields and Grain Nitrogen Concentration of Corn as Influenced by Fertilizer Nitrogen Rate

Knowledge of optimum fertilization for com production is required to increase crop yields while minimizing fertilizer costs. Field experiments were carried out from 1988 to 1993 to study the effects of fertilizer N rates on yield and N concentration of corn ( Zea mays L.) grain on a clay soil in Quebec. Grain yields and grain N concentrations generally followed a exponential relationship with increasing N fertilizer rates. The critical grain N concentration, defined as that associated with the highest grain yield, occurred at 285 kg N ha^-1 for all years except 1969 when it occurred at 170 kg N ha^-1. The critical grain N concentrations and grain yields over the years were found to be linearly related. The relationship between the critical grain N concentration and grain yield could serve as a diagnostic tool for N applications.     

玉米籽粒灌浆及脱水速率品种差异与相关分析

黑龙江省地处中国北方早熟春玉米区,无霜期短、热量资源不足是限制黑龙江省玉米产量和品质提高的主要因素,通过对10个玉米品种的灌浆速率、脱水速率、收获时籽粒含水量和产量等项目进行比较及差异分析,选择种植产量高、含水量低的玉米品种是解决这一矛盾的根本途径。结果表明：不同玉米品种不同灌浆期灌浆速率不同,‘四单19’、‘东农250’、‘吉单27’表现为中前期灌浆速率快,后期相对较慢,‘嫩单10’、‘兴垦3’、‘嫩单11’表现为中前期灌浆速率慢,后期相对较快的特点;不同灌浆时期品种脱水速率不同,‘四单19’、‘东农250’、‘吉单27’、‘嫩单10’在整个灌浆期脱水速率均较其他品种快,收获时籽粒含水量低于其他品种。并对供试杂交种进行综合评价,为选用优质高产玉米品种提供理论依据。     

6种植物对土壤中镉的富集特性研究

[目的]为了筛选出能适应湖南省重金属污染农田的镉移除植物,[方法]以甜高粱、生物质高粱、玉米、油葵、商陆、籽粒苋为材料,在醴陵市、株洲县和湘潭县重金属镉污染区开展田间试验,研究这6种植物对土壤中重金属镉的富集特性。[结果]结果表明：植株中镉的含量高低受植物品种和土壤中镉的含量影响较大,3个试验点中6种植物地上部分重金属镉的含量高低顺序为：籽粒苋＞商陆＞生物质高粱＞油葵＞甜高粱＞玉米,且株洲＞湘潭＞醴陵。除玉米外,其他植物地上部对重金属镉的富集系数均大于1,具备对镉的富集特性,其中籽粒苋对重金属镉的富集系数最高。[结论] 籽粒苋对镉有很强的富集性,是修复土壤重金属镉污染的良好材料。     

Evaluation of Grain Filling Rate and Duration in Bread and Durum Wheat, under Heat Stress after Anthesis

Bread and durum wheat genotypes were submitted to heat stress during the grain filling period, and relationships between grain weight and accumulated time from anthesis until maturity, using days after anthesis and growing degree days, were described by cubic polynomials. Maximum grain weight and the duration and rate of grain filling were estimated from the fitted curves. It was found that bread and durum wheat exposure to high temperatures significantly decreased grain weight and hastens physiological maturity (shortening the grain filling period). High temperatures significantly affected the rate (on a growing degree day basis) and duration (on Julian day units) of grain filling. The grain filling rate, on a thermal time basis, was positively associated with the final grain weight and the estimated maximum grain weight. The duration of grain filling does not appear to be a limiting factor for genotype grain weight stability, being mainly fixed by temperature. Grain weight of the controlled plants was positively correlated with the final and maximum grain weight of heat stressed plants. It was concluded that a high grain filling rate and a high potential grain weight are major traits that can be useful to improve heat tolerance of Triticum under Mediterranean environments.     

不同玉米品种子粒脱水速率研究

以郑单958、先玉335、农华101、登海11、中单909、正大12为研究材料,研究了子粒、苞叶、穗轴含水量及其脱水速率。结果表明：不同品种间的子粒、苞叶、穗轴含水量差异极显著,不同品种间的子粒脱水速率差异极显著。子粒含水量与苞叶、穗轴含水量呈极显著正相关,相关系数分别为0.777和0.267,苞叶含水量与穗轴含水量呈极显著正相关,相关系数为0.312。先玉335、农华101在子粒脱水前期较其他品种脱水快且快速脱水时间长,收获时（9月24日）的子粒含水量分别为25.40%和26.58%;符合机械收粒的标准,可作为机械收粒的备选品种。     

Grain Yields of Perennial Grain Crops in Pure and Mixed Stands

Perennial grain crops were examined in pure stands and in various mixtures for their grain yield potential in, and suitability for, low‐input systems on marginal land. The investigation was based on field experiments conducted at two sites characterized by marginal environmental conditions in south‐west Germany in 1999 and 2000. The experiments included perennial species of rye (Secale cereale × Secale montanum), intermediate wheatgrass (Thinopyrum intermedium), lupin (Lupinus polyphyllus) and linseed (Linum perenne). In some stands, white clover (Trifolium repens) was included as an undersown intercrop for improved N supply. It was found that maturation of the species differed by up to almost 6 weeks, and consequently the threshability of most mixed stands was not satisfactory. Nevertheless, mixtures of either of the grasses (rye or wheatgrass) with lupin or undersown clover proved to be more suitable than pure stands in most cases, for measures such as grain yield, weed suppression and stability of grain yield over years. The grain yield harvested in the experiments in 1999 was low, reaching about 2.7 t ha^?1 with rye, and decreased for most species in 2000. If improved genotypes were available, perennial grain crops could provide an alternative for arable cropping and set‐aside areas under marginal conditions.     

转基因植物中选择标记基因的控制策略

近年来,转基因植物中的选择标记的安全性问题引起公众关注,如何消除选择标记,培育无选择标记基因的转基因植物已成为基因工程研究的热点。本文系统介绍了通过共转化、转座子、染色体内重组和位点特异性重组消除选择标记及用正向选择标记基因代替负向选择标记基因手段培育无选择标记的转基因植物的发展策略。     

水氮胁迫对冬小麦籽粒灌浆速率影响的模拟研究

为定量分析水氮胁迫对冬小麦籽粒灌浆速率的影响,以‘济麦22’为材料,于2016—2017和2017—2018年度开展施氮试验。结合2017—2018年度试验资料,通过分析水氮胁迫对冬小麦籽粒灌浆速率的影响规律,引入氮素和水分影响因子,构建水氮胁迫对冬小麦籽粒灌浆速率影响的模拟模型S_(j,t)=S_(W3N300,t)×(1+F_N)×(1+F_W)。经2016—2017年小麦生长数据检验,除绝对误差占实测值比率d_ap略高外,RMSE值、平均绝对误差d_a以及相关系数r均显示模拟值和实测值有较高的一致性,说明实测值与模拟值吻合程度较好,所建模型可较好模拟水氮胁迫对冬小麦籽粒灌浆速率的影响。     

分子标记辅助选择改良优质水稻恢复系明恢63的稻米品质

明恢63是我国育成的一个籼型三系强优势恢复系,其直链淀粉含量适中,但是糊化温度和胶稠度较差,并且仍然存在心白.从控制稻米糊化温度的alk基因和控制香味的fgr基因编码区寻找插入缺失长度多态性(insertion deletion length polymorphism,InDel)位点,并开发出InDel标记进行辅助选择育种,经回交聚合向明恢63品种导入来自中国香稻的alk和fgr等位片段,改良品系的稻米糊化温度显著降低,胶稠度升高,具有了香味,并且心白粒率得到了降低.外观品质、蒸煮食味品质得到了显著的改善.     

Grain Weight Reductions in Wheat Associated with Semidwarfism: an Analysis of Grain Weight at Different Positions Within the Spike of Near-isogenic Lines

Semidwarf genes have made a major contribution to grain yield gains in wheat during this century. These genes have frequently been reported to increase grain number but decrease grain size. To analyse possible causes of this negative association between number of grains per head and mean grain weight, grains from different positions within the spikes were individually weighed in three isolines (standard-height, SH; semidwarf, SD; and dwarf, DD) of the spring wheat cultivar Maringa grown under field conditions. Dwarfing genes affected both grain number and grain weight. Increasing doses of Rht genes resulted in a decreased average grain weight (ca. 22 %) but in a greater increase in number of grains per m² (ca. 40%). Since the isogenic lines did not differ in either the number of spikes per m² or number of spikelets per spike, the frequencies of appearance of grains in the distal positions (florets 3 and 4) of the central spikelets and in the top spikelets of the spike was much higher for the SD and DD lines than for the SH line. Averaging across spikelets, basal grains (grains 1 and 2) of SH, SD and DD lines represented ca. 82, 73, and 69 %, respectively, of the total number of grains. On the other hand, grain 4 was almost absent in the SH line but represented around 10 % of the grains in the DD line. Averaging across lines and spikelets, basal grains weighed ca. 30 mg, which is approximately 20 % heavier than grain 3 (ca. 25 mg) and 85 % heavier than grain 4 (ca. 16 mg). Although there was a clear trend for a greater grain weight in the SH line (with no major differences between the SD and DD line) when basal grains were considered, grains 3 and 4 did not show any clear difference between lines. The fact that genotypes with Rht alleles had grains in the distal positions with a much higher frequency of appearance than in the SH line could be the main reason for their lower average grain weight. Therefore, the negative relationship between grain number and average grain weight might be not reflecting that competition for assimilates among grains of the DD and SD lines is stronger than that in the SH line.     

Estimation of Outcrossing Rate in Chickpea (Cicer Arietinum L.) Sown in Autumn

Gene flow via outcrossing from transgenic plants to relatives will be one of the most important concerns to grow of the transgenic chickpea (Cicer arietinum L.) in European Union (EU). This report is therefore focused on spontaneous outcrossing rate in chickpea. A total of 39 kabuli type mutants with white flower and one desi type with pink flower were grown to estimate spontaneous outcrossing rate. Outcrossing rate ranged from 0.0 to 1.25% in mutant materials. Since labelling threshold for transgenic contamination in food and feed in European Union (EU) is 0.9%, outcrossing rate of 1.25% is higher than threshold of 0.9% in EU, and this result suggests that cultivation of transgenic chickpea will be under high risk to be contaminated chickpeas in neighbourhood fields.     

从天冬-玉米的示范种植探讨"粮-药间套"增益模式

采用天冬单作、玉米单作和天冬-玉米套作3种种植模式,考查了整个生产过程中其主要生产资料和劳动力的投入以及产值等关键指标.对不同种植模式的经济效益对比分析结果表明,天冬-玉米套作比天冬单作增收21.8%,比玉米单作增收564.9%.天冬单作虽比玉米单作增收446.0%,但天冬种植三年后才能收获药材,没有短期收益.因此,3种模式中天冬-玉米套作的效果最佳.这一研究结果为种植业提供了一条"粮-药间套"的有效增益模式.     

小麦籽粒灌浆速率及粒重QTL初步研究

为了对小麦不同发育时期灌浆速率及千粒重进行动态QTL初步定位,并进行遗传分析,通过01-35×6044杂交得F1代,后经连续多年“一粒传法”获得F9代重组自交系,利用Mapmaker/version 3.0计算标记间距离并绘制遗传图谱,结合田间表型数据采用Win QTL Cart 2.5软件的方法研究小麦不同发育时期灌浆速率及千粒重QTL定位情况及其效应。结果共检测到13个小麦灌浆速率及千粒重QTL,这些QTL大部分是位于2A染色体上,部分位于6A、5A、4A染色体上。其中千粒重QTL 2个,可解释表型变异的9%和33%;平均灌浆速率QTL 3个,可解释表型变异的6%~18%;最高灌浆速率QTL 1个,可解释表型变异的11%;最高灌浆速率出现的时间QTL 1个,解释7%的表型变异;第一、四时期各1个,分别解释表型变异的12%和16%;三、五时期各2个,分别解释表型变异的8%~9%和9%~10%。通过对不同时期小麦灌浆速率和粒重QTL定位,探索了控制灌浆速率的基因表达的时空特性,为灌浆速率及千粒重的QTL精细定位和分子标记辅助选择奠定基础。     

近10年来甘肃省粮食生产现状及增产途径分析

明确甘肃省粮食生产能力及其进一步提高的途径,对未来保障区域粮食安全具有重要意义。通过调查近10年来甘肃省耕地面积、粮食播种面积、粮食总产量、粮食单产等数据资料,探讨了耕地面积、粮食播种面积、粮食总产量和粮食单产之间的相互关系,以阐明甘肃省粮食生产的潜力及其主要影响因素。结果表明,甘肃省耕地面积和粮食播种面积在近10年间呈先下降后上升的趋势,二者呈显著线性相关（P<0.01）;粮食总产量和单产波动上升,但粮食播种面积的变化对粮食总产量无显著影响,单产提高是引起粮食总产量增加的主要因素。分析认为提高单位面积的粮食生产能力是保障甘肃省粮食安全的主要出路,而提高旱地粮食单产则是实现甘肃省新增25亿kg粮食的主要突破口。     

Grain Yield and Quality of Durum Wheat Landraces in a Dry Mediterranean Region of Northern Syria

Twenty-two durum wheat landraces of various origins were evaluated for performance and stability of grain yield, protein content and gluten strength (SDS sedimentation volume) at two sites of Northern Syria situated in the drought-prone part of the local durum wheat belt. Yield was recorded in three seasons, while protein content and SDS volume were assessed in two seasons only. A high “entry X environment” interaction was observed for all traits, which was significantly attributable to heterogeneity of entry regressions on the environmental mean for grain yield only. Compared to the recently-bred, widely-grown variety ‘Sham I’, some landraces showed somewhat similar yield responses, whereas others proved more stable without being significantly lower yielding. Significant variation was found for SDS volume, though only few of the best-ranking landraces for this trait also possessed an acceptable yield level. The entries did not significantly differ for protein content. The broad sense heritability estimates obtained for grain yield (0.59) and SDS volume (0.89) highlighted the interest in some of the landraces examined for improving grain yield and quality in the region.     

小麦穗内芒长与粒重关系的粒位效应

为了探索有芒小麦穗内芒长与粒重的关系,本试验选取两个小麦品种‘煤生0308’和‘煤生5号’,对其不同粒位的芒长和粒重进行了研究。结果表明,芒长与粒重呈显著正相关,相关系数分别为0.373（P=0.0046）和0.267（P=0.0256）。然而,在相同粒位不同小穗位,芒长与粒重的相关程度是不同的。在第一粒位,芒长和粒重相关性不显著;在第二粒位,芒长和粒重呈显著正相关,相关系数分别为0.3814（P=0.0454）和0.4802（P=0.0170）;在第三粒位,芒长和粒重呈极显著正相关,相关系数分别为0.8455（P=0.0003）和0.8516（P=0.0001）。     

中国粮食主产区主要粮食作物比较优势与发展对策研究

粮食生产的发展受多种因素的综合作用,首先分析了自然、经济、社会等因素对粮食生产的影响,在此基础上,研究了我国长江中下游流域、黄淮海流域和东北三省三大粮食主产区1979—2003年间不同作物在不同区域的单产比较优势、规模比较优势和综合比较优势,总结了五大粮食作物不同区域的优势表现。最后提出发挥我国粮食主产区比较优势,提高我国粮食主产区粮食综合生产能力的思路与对策。     

小麦粒重相关基因TaCYP78A5功能标记开发及验证

为了开发小麦粒重相关基因TaCYP78A5 (Triticum aestivum Cytochrome P450 78A5)的功能标记,挖掘与千粒重性状相关的优异等位变异,本研究通过对30份不同品种小麦TaCYP78A5启动子区测序及比对鉴定,并根据SNP位点差异开发TaCYP78A5-2A启动子区功能标记CAPS-5Ap。结果表明,在30份不同小麦品种中TaCYP78A5-2A启动子区域出现5个SNP位点差异,可将30份不同品种小麦分为TaCYP78A5-2Ap-HapI和TaCYP78A5-2Ap-HapII两种单倍型;以323份现代育成小麦品种验证发现,TaCYP78A5-2Ap-HapI的分布频率为17.96%,TaCYP78A5-2Ap-HapII的分布频率为82.04%,表明CAPS-5Ap标记可用于小麦TaCYP78A5-2A启动子序列2种单倍型的鉴定。此外,关联分析发现, CAPS-5Ap标记与粒重相关,且TaCYP78A5-2Ap-HapII是提高千粒重的优异单倍型。研究结果为小麦分子标记辅助选择和性状改良提供理论依据。     

粳稻穗部不同部位米粒直链淀粉含量的差异分析

直链淀粉含量是影响稻米品质的一个重要指标. 本文通过穗内不同米粒间、粒内不同部位间直链淀粉含量的测定明确同一品种同一穗不同籽粒间的差异可高达14.2%, 稻穗上部、一次枝梗、先开花结实或粒重较高的米粒直链淀粉含量较高; 稻穗基部、二次枝梗或未完全成熟、迟开花结实或粒重较低的米粒直链淀粉含量较低. 米粒胚侧半粒与