两系杂交稻两优培九的生态适应性研究及其种植区域规划

【目的】实现两系超级稻两优培九大面积种植,分析其生态适应性,合理规划和选择最适宜种植区域。【方法】在南方稻区8个试验点连续2年进行区域生态适应性试验。根据水稻生长发育和产量形成与种植环境相协调一致的原理,采用生长解析方法,选择生育期（GD）、生长速率（ ）、灌浆速率（ ）和产量指数（YI）为分析要素,分析两优培九在中国南方稻区的适应性。【结果】GD、 、 都可以建立决定系数较高的环境模型,YI可以由GD、 、 综合表达。两优培九出穗的高温促进率,短日下为5级,长日下为3级,短日促进率为4～5级,为中等感光型,在华南双季稻区的生育期稳定性低于长江中下游稻区及江淮稻区。 等值线呈东南-西北走向,与该地区的夏季温度分布基本一致。长江中下游稻区和江淮稻区是 距平+10%的高值区,华南双季稻区为距平负值区。 除了受灌浆结实期的环境影响外,还受到抽穗前积累的干物质量（GW）运转的影响。 等值线基本呈纬向分布,距平-20%线在24°N以南,大致与两优培九作双季连作稻种植的北界一致。24～28°N为 距平负值区域,28～30°N为 距平正值区域,距平+20%区域在江淮稻区。因地势特点, 和 在四川盆地及洞庭湖地区有相对低值区,在云贵高原河谷和湘、黔、川交界的低山丘陵有相对高值区。两优培九YI在南方稻区自南向北递增,平均达到（10.01±2.71）t•ha-1。其中,华南双季稻区为（7.31±1.00）t•ha-1,华中单双季稻区为（9.34±1.28）t•ha-1,长江中下游和江淮稻区为（11.93±2.04）t•ha-1,洞庭湖地区和四川盆地是7.5～9.0 t•ha-1的低YI区,云贵高原河谷地区有15 t•ha-1以上的生产潜力,南方丘陵也有10.5 t•ha-1的高YI区。【结论】在种植区规划上,两优培九宜作为一季中稻,继续向28～30°N华中单双季稻区北部最有利的生态区域发展。     

南果梨适宜采收成熟度的研究

对南果梨适宜采收期进行了研究。试验结果表明,早期采收果实中可溶性固形物含量较低,果实呼吸代谢旺盛,耐贮性差;晚期采收的果实可溶性固形物含量增加,适合鲜食,不适合长期贮藏;南果梨较为适宜采收期应为9月9日前后。果实硬度、可溶性固形物含量、种子转色指数可作为确定采收成熟度的指标。     

不同种肥施用水平对大果沙棘苗期生长的影响

在西宁地区采用裂区设计将不同品种沙棘种植于不同种肥用量下进行实验结果表明：中华沙棘在其株高、根长、根茎、干重四项指标的测定中均高于向阳、楚伊两个大果沙棘品种。在300 kg/hm^2的施肥水平下,大果沙棘的苗期株高、根长、根茎、干重生长量最大。品种和不同磷酸二氨的施肥量的互作显著,中华沙棘在低肥条件下的生长量大,在高肥条件下向阳、楚伊的生长量大。     

Critical period for grain number establishment of near isogenic lines of two- and six-rowed barley

In barley no studies have attempted to pinpoint the critical period for grain number determination, and it is frequently stated that the critical period is similar to that of wheat. However, there are important differences between the species and among barley genotypes (i.e. two- and six-rowed types) suggesting that this assumption requires testing. The objectives of this paper were (i) to determine the critical period for grain number determination in two- and six-rowed barleys, and (ii) to identify which yield components were more sensitive to changes in incident radiation during that period.

Two field experiments were conducted using two pairs of near isogenic lines differing only in the spike type. Shading was imposed at different periods throughout the crop cycle (from 60 days before heading to 15 days after) to reduce incident solar radiation approximately 70%.

The critical period for grain number determination tended to be slightly earlier in two- (ca. between 40 and 10 days before heading) than in six-rowed barleys (ca. between 30 days before heading until that stage). In terms of the external phenology, the beginning of the critical period for setting grains was 10 days after the beginning of stem elongation, and 10 days before flag leaf appearance in two- and six-rowed lines, respectively. Changes in the number of grains per unit area were correlated with crop growth rate during the critical period for yield determination.     

树型金银花花蕾大小与花粉发育关系的研究

[目的]研究树型金银花花蕾大小与花粉发育的关系。[方法]采摘未开树型金银花花蕾,通过不同染液染色,获得最佳观察效果,固定、测量花蕾长度、制片、镜检。[结果]树型金银花花药用醋酸洋红染色效果比美蓝染色效果好。花药发育的时期和花蕾外观形态之间的对应关系为:花蕾长度0.48～0.71 cm处于单核早期,达到71.0%;长度在0.72～0.89 cm处于单核中期,达到65.0%;长度在0.90～1.02 cm处于单核晚期,达到67.3%;长度在1.02～1.19 cm处于有丝分裂前期,达到60.8%;长度在1.19～2.32 cm处于二核期,达到59.8%。[结论]通过观察树型金银花花蕾外观形态,可以直观确定花药发育时期,为花药单倍体培养奠定基础。     

Genetic Diversity of European and Chinese Oilseed Brassica rapa Cultivars from Different Breeding Periods

The Brassica oilseed crops went through two major breeding bottlenecks during the introgression of genes for zero erucic acid and low glucosinolate content, respectively, which may lead to reduced genetic biodiversity of the crop. This study investigates the impact of these bottlenecks on the genetic diversity within and across European and Chinese winter B. rapa cultivars. We compared eight cultivars from Europe and China, representing three different seed qualities from three different breeding periods： （1） high erucic acid, high glucosinolates （＋＋）; （2） zero erucic acid, high glucosinolates（0＋）; （3） zero erucic acid, low glucosonolates （00, canola quality）. Diversity was estimated on 32 plants per cultivar, with 16 simple sequence repeat （SSR） markers covering each of the B. rapa linkage groups. The analysis of molecular variance （AMOVA） showed that genetic variations within cultivars, across cultivars and across regions （Europe and China） were significant, with about 60% of the total variation within cultivars. There was a slight, but non-significant loss in genetic diversity within cultivars when comparing the three breeding periods as indicated by effective number of alleles （2.39, 2.23, and 1.99 for breeding periods 1, 2, and 3, respectively）, Shannon information index （0.93, 0.90, 0.75）, and expected heterozygosity （0.51, 0.49, 0.42）. By cluster analysis （UPGMA dendrogram） and principal coordinate analysis, Chinese and European cultivars were clearly divided into two distinct groups. In conclusion, quality improvement did not significantly reduce the genetic diversity of European and Chinese B. rapa cultivars.     

大型泄洪洞衬砌混凝土施工期温度场和温度应力的仿真计算

【目的】探明地下衬砌混凝土出现裂缝的原因,研究进一步采取综合温控措施防裂的有效性和合理性。【方法】结合工程实际情况,在考虑混凝土热力学参数随混凝土龄期的变化,以及坝体分层浇筑过程对温度应力影响的基础上,利用大型有限元软件对泄洪洞衬砌施工过程中的温度场和温度应力进行了三维仿真计算。【结果】仿真结果给出了衬砌混凝土温度场、温度应力分布及其随时间变化的规律,即于开浇后的第2天达到最大温度值,第3天即开始出现较大拉应力值,而极值出现在中后期。【结论】在混凝土浇筑过程中,应采取降低浇筑温度等措施;在浇筑后的10~28 d温降期间,要对混凝土表面施行流水养护等温控措施,严格各项施工规范。     

水稻亲本、杂交后代的成熟期倒伏指数及关系研究

以籼型三系不育系宜香1A、II-32A、冈46A和恢复系宜恢7633、宜恢7008、宜恢1525等为材料,通过对亲本和杂交后代倒伏指数的分析,发现母本、父本各节间倒伏指数存在较明显的差异,倒3节间的倒伏指数差异达极显著水平.这种差异直接影响着后代倒伏指数的变化,特别是母本对后代的影响效果更为明显.父母本抗倒能力强,则后代较易表现强的抗倒力,同时也受父母本间互作效应和它们与环境互作效应的综合影响.     

贮藏期对花生种质籽粒成分影响研究

常温干燥贮藏是植物种质资源保存的重要方式之一。研究表明,在常温干燥条件下,经过11年的保存,花生不同类型籽粒成分发生程度不同的变化,其中总糖含量随贮藏时间而增加,蛋白质和粗脂肪含量整体呈降低趋势,脂肪酸中除油酸含量随贮藏时间延长而升高外,棕榈酸与亚油酸含量均降低。VE除多粒型与中间型外,其余类型花生种质均随贮藏时间延长而降低。同时,花生种质的外观品质性状不随贮藏时间延长而发生显著变化。