一流专业建设背景下实践课程的改革优化——以“种子科学综合实践”课程为例

实践教学是提高大学生实践能力的重要途径,进一步完善实践教学机制是一流本科专业建设的重要任务。“种子科学综合实践”是国家级一流本科专业种子科学与工程的专业综合实践课程,具有专业性强、涉及知识广、实践过程长、操作复杂等特点。针对课程中存在的问题,通过丰富实践内容、转变教学方式、完善评价体系、强化课程思政、优化教师队伍,进一步完善了课程教学体系,有效改善了课程教学效果。

Quantifying the attribution of model bias in simulating summer hot days in China with IAP AGCM 4.1

本文利用IAP大气环流模式1961–2005年的模拟结果,分析发现模式虽然可较好模拟出中国大陆夏季高温日数的空间分布特征,但对高温日数的模拟则普遍高估。通过分析观测和模式模拟的日最高温度的概率分布特征,定量评估了日最高温的均值和方差的模拟偏差对模式高估极端高温日数的相对贡献,指出日最高温度均值的模拟偏高是模式高估高温日数的主要原因,但日最高温方差的模拟偏差对高温日数的高估也有重要影响,以江淮地区8月份为例,其贡献可达22%。进一步分析表明,IAP模式未能模拟出江淮流域1980s年代前后极端高温日数的年代际减少,主要归因于模式未能模拟出1980s前后日最高气温均值的年代际减小,而模式未能模拟出日最高温方差的年代际减弱也起很大作用。

Uncertainty in Dust Budget over East Asia Simulated by WRF/Chem with Six Different Dust Emission Schemes

In this study, the dependence of dust budgets on dust emission schemes is investigated through the simulation of dust storm events, which occurred during 14–25 March 2002, over East Asia, by the Weather Research and Forecasting with Chemistry(WRF/Chem) model coupled with six dust emission schemes. Generally, this model can reasonably reproduce the spatial distribution of surface dust concentration; however, the simulated total dust budget differs significantly with different emission schemes. Moreover, uncertainties in the simulated dust budget vary among regions. It is suggested that the dust emission scheme affects the regional dust budget directly through its impact on the total emitted dust amount; however, the inflow and outflow of dust aerosols simulated by different schemes within a region also depend on the geographical location of the dust emission region. Furthermore, the size distribution of dust particles for a specific dust emission scheme has proven to be important for dust budget calculation due to the dependence of dust deposition amount on dust size distribution.

The effects of grain texture and phenotypic traits on the thin-layer drying rate in maize(Zea mays L.) inbred lines

To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different（P〈0.05） among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants（k and N） in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.

Factors influencing seed reserve utilization during seedling establishment in maize inbred lines

Strong seedlings are essential for high yield.To explore the foundation of strong seedlings,we investigated various factors influencing the conversion and distribution of seed storage reserves during seedling establishment in maize inbred lines.Three maize inbred lines were used to explore the effects of seed size,seed vigor,illumination duration,temperature,water content,and salt concentration of the seedling medium on the utilization of seed storage reserves during seedling establishment.The results showed that the conversion rate of small seeds was 3.69 to 17.71%higher than that of large seeds.Moreover,prolonged illumination time was conducive to the formation of strong seedlings.However,low temperature,drought stress and salt stress reduced the conversion rate of seed storage reserves and increased the root/shoot ratio.These results could be used to guide field management during seedling emergence and develop improved germplasm with a high conversion rate of seed storage reserves.

MJO potential predictability and predictive skill in IAP AGCM 4.1

MJO模拟及预报是现阶段大气科学研究的前沿问题。本文利用中科院大气物理所大气环流模式(IAP AGCM4.1)的集合回报结果,分析了MJO潜在可预报性及预报技巧。研究表明IAP AGCM4.1对MJO有着较好的潜在可预报性,且集合预报的潜在可预报性要明显优于单样本预报;就MJO的预报技巧而言,集合预报同样优于单样本预报;模式对MJO的预报技巧还显著依赖于预报初始时刻的MJO状态,初始MJO信号越强,模式对MJO的预报技巧也越高,且更接近可预报性的上限。

玉米自交系花期耐热能力的评价

对138个玉米自交系在泰安2016、2017年连续两年夏天进行花期套网袋授粉,结合玉米自交系自然开放授粉,研究玉米自交系授粉结实率的差异,通过套袋和自然开放授粉区分花丝造成的不育还是花粉引起的不育,建立玉米自交系耐热性评价,并筛选出耐热的玉米自交系,结果表明,根据高温下两年都遇到日平均温度在30℃以上自然开放授粉结实率为依据将材料划分为4类,高度耐热性的材料、耐热性中等的材料、耐热性较弱材料、不耐热材料。两年都遇到网袋授粉日平均温度在30℃以上结实率偏低的材料有133个,因为花丝耐热性差造成结实率低的材料68个,因花粉耐热性差造成结实率低的材料65个,筛选出5个耐热性好的材料京2416、B尖八-1-2、B138-1-2、(488/8001-1-4)-2-1-2、Pr07500-1-1。

化学调控剂对玉米自交系株高及穗上各节间长度的影响

以玉米自交系郑58和PH6WC为研究材料,在不同时期喷施赤霉素和乙烯利＋油菜素内酯调节株高。结果表明,郑58在17片可见叶期,喷施200 mg/L赤霉素效果最佳,倒1节节间长度提升幅度与对照达显著性差异;PH6WC对赤霉素反应不敏感。郑58在14片可见叶期,喷施100 mg/L乙烯利＋0.1 mg/L油菜素内酯降低株高的效果最佳,倒2节至倒6节节间长度降低幅度均与对照达显著性差异;PH6WC在17片可见叶期,喷施200 mg/L乙烯利＋0.1 mg/L油菜素内酯降低株高效果最佳,倒1节至倒6节节间长度降低幅度均与对照达到显著性差异。不同自交系对化控剂处理的最佳时期和浓度均有差异。

玉米自交系耐密性的SNP标记发掘

以238份玉米自交系为试验材料,设置两个种植密度水平,研究不同密度对农艺性状的影响,筛选用于评价玉米自交系耐密性的指标并建立耐密性评价体系。结合关联分析找到相应的SNP标记,将标准化值变异系数较大的指标作为耐密性指标。结果表明,单株产量降幅、秃尖长差值、ASI差值可作为玉米自交系耐密性评价指标。利用建立的评价体系从本试验材料中筛选10个耐密性材料,包括B283-1、良玉S122、丹黄212、L201、D25-2-1-1-1、pr07007-1、pr07438-2-2-1、黄早四、SN7135和Y32-1-1-1-1-1。两个环境条件下,共检测到单株产量相关联的4个较重要的(-Log p>3.0)SNP标记,位于第3、4、5和9染色体上;检测到秃尖长相关联的13个较重要的(-Log p>4.5)SNP标记,位于第1、4、7和10染色体上;检测到ASI相关联的12个较重要的(-Log p>4.5)SNP标记,位于第1、4和8染色体上。