不同株型水稻叶倾角群体分布的模拟

 以株型因子为参数,建立了不同株型品种水稻叶倾角分布模型。对该模型进行验证,模拟值与实测值的1∶1回归直线的R2和RMSE分别为0.9472和3.93%。用本模型对3种株型、6个冠层高度和7个生长期的水稻冠层叶倾角分布的模拟结果表明,3种株型水稻叶倾角分布不同,紧凑株型的两优培九叶倾角较大,叶片挺立;松散株型的汕优63叶倾角最小,叶片披垂;中间型两优Y06介于两者中间,与实际观察结果一致。同一品种7个生长期叶倾角分布不同,从分蘖期到孕穗期,冠层叶倾角逐渐变大,叶片逐渐挺立;从孕穗期到成熟期,两优培九叶倾角变化不明显,汕优63和两优Y06则逐渐变小,叶片逐渐披散,其中,汕优63尤为明显。同一品种相同生长期的 6个冠层高度叶倾角分布不同,随着冠层高度增加,3个品种的分层LAI均减小,两优培九叶倾角变化不大,汕优63逐渐增大,两优Y06逐渐减小。试验证明该模型具有良好实用性。     

水稻叶倾角分子机制及育种应用的研究进展

水稻叶倾角是指叶片与茎秆之间的夹角,叶倾角影响叶片光合作用速率,与株型和产量密切相关,如直立叶片就是水稻理想株型形态因素之一。叶倾角的大小受到多种植物激素的调控,是油菜素内酯、生长素、赤霉素、茉莉酸等多种激素相互作用的结果,另外,其他因素如根系分布、叶片大小、生长环境等也会对水稻叶倾角大小产生一定的影响。本文根据水稻叶倾角的研究进展,着重从叶枕的发育、激素水平及其他因素等方面,对水稻叶倾角的分子机制及其在育种中的应用进行阐述与总结,以期为水稻株型的分子设计育种提供参考,为进一步提高水稻的产量奠定理论基础。     

浙江省大豆红冠腐病的病原菌鉴定

大豆红冠腐病(red crown rot of soybean,RCR)是世界范围内的重要的大豆病害之一,病害症状为罹病植株茎基部变红,表面聚集了大量橙红色球状子囊壳。对采自浙江省桐庐县的疑似大豆红冠腐病的病原进行分离和培养,从分离获得的菌株中选择1个代表菌株ZJHZ01进行后续试验和分析,为浙江省大豆产区的红冠腐病的防控提供依据。致病性测定结果表明:菌株ZJHZ01接种大豆茎基部可引起发病,回接症状与田间自然发病症状较为相似。病原菌落初为白色,后变为鹅黄色,菌落中可产生大量红褐色微菌核和厚垣孢子,在PDA、V8和康乃馨叶片培养基中极易产生子囊孢子,与已报道的大豆红冠腐病菌的菌落形态特征相似,初步认为ZJHZ01为冬青丽赤壳(Calonectria ilicicola)。进一步在分子生物学水平上,对其TUB、HIS和EF-1α序列进行PCR扩增和测序,对比Gen Bank中已经录入的丽赤壳属相应序列。基于以上3种基因联合序列,通过采用邻接法构建了的系统发育树。结果表明:菌株ZJHZ01与Gen Bank中C.ilicicola菌株GDBL01存在着极高的同源性,序列相似度达到了99%以上。通过对浙江省桐庐地区大豆产区的大豆病株的病原菌进行致病性、形态学和分子生物学分析,明确了浙江省桐庐大豆产区的红冠腐病是由C.ilicicola侵染所致,这是该病害在浙江省的首次报道。     

小麦茎基腐病抗性QTL的分析

为挖掘更多的茎基腐病抗性QTL用于分子标记辅助育种,以中抗茎基腐病品种CI12633和感茎基腐病品种扬麦158的重组自交系群体为材料,采用SSR和SNP等分子标记对群体中的94个家系进行基因型分析,绘制遗传连锁图,并结合3次室内群体的茎基腐病抗性鉴定结果对小麦茎基腐病抗性QTL进行定位.结果表明,与小麦茎基腐病抗性相关...     

Inclination Angle Affects Ozone Injury in the Flag Leaf of Rice

Abstract

To evaluate the effect of inclination angle of the leaf on the leaf injury of rice by O₃, we examined the effect of a 5-hr exposure to 0, 0.1, 0.3 cm³ m-³ O₃, abbreviated as O⁰, O^0.1 and O^0.3, respectively, of the flag leaf using natural-light gas-exposure chambers. The middle portion of the flag leaf was set horizontally using lead weights (H plant) and it was compared with a non-treated, erect leaf (E plant). Gas exchange and chlorophyll fluorescence were measured immediately before, immediately after, and 1 and 3 d after the start of the exposure. The net photosynthetic rate, stomatal conductance and operating quantum efficiency of photosystem II (F_q’/F_m’) were decreased by the exposure to O₃. Furthermore, the inhibitory effects of O^0.1 and O^0.3 on the H plants were severer than those on the E plants. The maximum quantum efficiency of photosystem II (F_v/F_m) in the leaf of H plants decreased immediately after exposure to O₃. These results indicate that the weaker inhibitory effect of O₃ on the erect leaf depends on the lower light intensity at the leaf surface, rather than the horizontal leaf position.

Key words: Ascorbic acid, Chlorophyll fluorescence, Gas exchange, Leaf inclination angle, Oryza sativa, O₃, Quantum efficiency.     

Root architecture of sorghum genotypes differing in root angles under different water regimes

Plant root architecture offers the potential for increasing soil water accessibility, particularly under water-limited conditions. The objectives of this study were to evaluate the root architecture in two genotypes of sorghum (Sorghum bicolor (L.) Moench) differing in root angles and to assess the influence of different deficit irrigation regimes on root architecture. The response of two sorghum genotypes, ‘Early Hegari-Sart’ (EH; steep root angle) and ‘Bk7’ (shallow root angle) to four irrigation treatments was investigated in two replicated outdoor studies using large pots. The results indicated that EH possessed steeper brace and crown root angles, fewer brace roots, greater root biomass, and root length density than Bk7 at deeper soil depths (i.e., 15–30 and 30–45 cm) compared with a shallower depth (i.e., 0–15 cm). Across the soil profile, EH had greater root length density and length of roots of small diameter (<1 mm) than Bk7. Accordingly, EH showed more rapid soil-water capture than Bk7. Different levels of irrigation input greatly affected root architecture. Severe deficit irrigation (25% of full crop transpiration throughout the season) increased the angle and number of crown roots, root biomass, and root length density compared with 75 and 100% of full crop transpiration treatments. Consequently, root system architecture can be effectively manipulated through both genotypic selection and irrigation management to ensure optimal performance under different levels of soil available water.     

雷州尾叶桉树冠指标与抚育间伐关系的探讨

通过对雷州尾叶桉树冠有效受光面积、树冠比率、树冠投影面积进行调查研究,分别用树冠有效受光面积、树冠比率、投影面积与胸径建立一元幂函数回归方程进行研究与分析,结果表明树冠有效受光面积公式对指导培育中径材较好;树冠比率与树冠投影面积公式的回归效果基本一致,对指导培育小径材较为理想,并利用上述回归公式编制单株营养面积、公顷立木株数和公顷基面积表为尾叶桉人工林的抚育间伐设计与施工提供理论依据。     

窄冠黑杨窄冠黑白杨的选育(I)田间试验及结果分析

通过杂交育种，苗期选择，无性系测定，选出了6个窄冠黑杨，1个窄冠黑白杨无性系。前者生长量接近对照I-69/55和中林46，冠幅比对照小1/2—1/3，耐盐碱能力较强，容易扦插繁殖，造林成活率高。后者生长量与窄冠白杨3号相当，冠幅比窄冠白杨3号更窄，繁殖方式同一般毛白杨。两类品种均为适合于农田林网及农林间作的杨树新品种。     

PCI术中冠脉激惹现象的临床诊治分析

目的探讨冠脉激惹现象的发生和处理方法 .方法采用PCI方法处理晚期冠脉支架内血栓合并支架外血管痉挛的病例发生冠脉激惹现象,应用药物和PCI进行处理.结果应用解痉药物无效,应用PTCA方法则病变加重,植入支架后TIMI血流达到Ⅲ级.结论冠脉激惹现象处理应以使用解痉药物为主,适当应用PTCA,药物和PTCA无效时,应及时给患者植入支架.