香软米滇屯502的选育

 主要介绍了利用云南高杆大穗米质特优的毫皮作母本与省协作组选育的株型紧凑、抗性强的香糯米滇侨20杂交,选育出高产优质抗病香软米新品种——滇屯502,同时系统地介绍了软米、香米、香软米的选育,供育种单位参考.     

三种氮素营养快速诊断方法在油菜上的适宜性分析

通过大田试验研究了SPAD仪法、硝酸盐反射仪法和光谱仪法在油菜氮素营养快速诊断上的适宜性。试验设施氮0、60、120、180、240、300和400kg/hm2处理,在八叶期、十叶期和蕾薹期对各处理SPAD值、冠层归一化植被指数（NDVI值）和硝酸盐含量进行检测,并测定各时期油菜生物量和收获期籽粒产量。对不同施氮量下的油菜产量进行显著性检验及方程拟合,并对三种诊断方法各测定指标与氮肥用量、籽粒产量进行相关分析。结果表明,油菜施氮量与籽粒产量具有较好的相关关系,满足氮素营养快速诊断要求。三种诊断方法中,硝酸盐反射仪法能在一定程度上反映油菜氮素营养状况,但受油菜生理特性（苗期生物量小、蕾薹期氮素奢侈性吸收等）影响,诊断结果的可信度和稳定性不高。光谱仪法比较适宜于油菜蕾薹期氮素营养诊断,但存在追肥时期过晚、操作不方便等缺点。综合分析认为,SPAD仪法诊断结果稳定,并且具有快速、简便、低耗等优点,适合于油菜氮素营养快速诊断。     

应用叶绿素仪SPAD-502进行马铃薯氮素营养诊断的可行性

SPAD-502是用于快速测定叶绿素相对含量的一种便携式仪器。被尝试用于进行作物氮素营养诊断,其具有快速、简便、适时、无损的特点。目前在禾谷类作物上已有很多研究成果并已开始用于指导施肥实践,在马铃薯上前人也井始了一些探索性的研究。马铃薯植株叶片形态虽具有一定的特殊性。即叶片为复叶,不能照擞禾本科作物上的研究成果,但综合分析SPAD-502的特点以及禾扭件作物氮素营养诊断的研究成果可以推断,通过系统研究,完全可以建立一掀有效的马铃薯氮素营养SPAD-502诊断指标体系。在指标体系的建立过程中,需确立适合的诊断叶位并提出有效的方法消除氮素之外其他因素对SPAD读数的影响。     

玉米杂交种丹玉502（丹5115）选育与应用

丹玉502是丹东农业科学院以自选系丹1705为母本,自选系丹765为父本组配而成的玉米单交种。通过辽宁省两年区域试验,平均比对照种郑单958增产6．4％,该品种具有适应性广、抗倒伏、多抗各种病害、高产稳产、生育期适中、品质好、边行优势不明显等特点,是值得北方春玉米区重点推广的新品种。关键词：玉米杂交种：丹玉502;品种选育     

落羽杉属4个新品种

'中山杉405','中山杉406','中山杉407'和'中山杉502'是以墨西哥落羽杉为母本、落羽杉为父本通过人工授粉杂交选育所获得的优良无性系,具有速生、耐水湿、耐盐碱、树形挺拔、主干通直圆满,抗风力强,适应性广,景观价值高等优良特性,可在江苏、浙江、上海、重庆、云南等地区栽植.     

冬油菜叶片SPAD的时空分布和氮素诊断的叶位选择

在大田试验条件下测定分析不同施氮水平冬油菜关键生育期SPAD值的时空分布特征,并对不同叶位及叶片不同部位SPAD值与叶绿素含量、叶片含氮量、植株全氮含量及籽粒产量之间的相关性进行分析,探求应用SPAD仪诊断油菜氮素营养状况的最佳测试叶位及位点。结果表明,油菜主茎顶部4片完全展开叶SPAD值存在显著空间差异,增加施氮量能显著提高各叶位叶SPAD值,同时减少叶位间的差异;六叶期、蕾薹期以顶4叶（TL4）SPAD值对氮素的敏感性最大,初花期和盛花期则最低。不同部位间,六叶期和初花期以中部SPAD值对施氮量增加的响应最敏感,盛花期则最迟钝,蕾薹期介于顶部和基部之间。综合分析认为,应用SPAD仪监测油菜氮素营养状况的最佳测试叶位和位点为主茎顶4片完全展开叶中部,该部位SPAD值与叶绿素含量、叶片含氮量和植株全氮含量之间的相关性均达到显著或极显著水平,满足氮素营养快速诊断的要求。     

SPAD-502叶绿素仪在烤烟生产中的应用研究

采用田间试验的方法,研究了SPAD-502叶绿素仪与烤烟叶绿素含量的关系,探讨SPAD-502叶绿素仪在烤烟生产中的应用前景。研究结果表明:叶绿素仪在烤烟上的最佳测量部位为叶片基部;不同叶位、不同成熟度烟叶的叶绿素仪读数与叶绿素含量之间呈显著相关,其线性关系可用方程y=ax b来拟合。     

利用 SPAD-502对高山杜鹃氮素营养的快速诊断研究

利用SPAD-502型叶绿素计测定了不同氮水平下高山杜鹃不同生长时期、不同叶位的SPAD 值,分析SPAD值与叶绿素含量和叶片总氮含量的关系。结果表明,不同生长期第1轮和第2轮叶片的SPAD值与叶绿素含量均呈显著线性正相关,其中新梢生长期第1轮叶片的SPAD值与叶绿素含量的相关性最强,而叶绿素各参数中对SPAD值影响最大的是叶绿素b的含量。在不同氮水平下, SPAD值及相对叶色差与单位干重的总氮含量具有显著线性正相关关系, SPAD值的变化能够反映60％的单位干重叶氮含量的变化。因此,可以利用SPAD-502型叶绿素计对高山杜鹃进行快速、无损的氮素营养诊断。     

Estimating the Mean Leaf Inclination Angle of Wheat Canopies Using Reflected Polarized Light

Abstract

In this study, we extended previous work linking the polarization of reflected light from crop canopies with characteristics of the canopy structure, such as the leaf inclination angle. We obtained reflectance and polarized reflectance in 8 spectral bands from the canopies of two varieties of wheat, planted in plots fertilized with a basal dressing and topdressed at the jointing and booting stages. The optical measurements were carried out on 3 clear-sky days when the plants were at the stem-elongation, heading and ripening stages, respectively. On each measurement date, we assessed the leaf orientation geometry of the plants using a Plant Canopy Analyzer (LAI-2000), measured the leaf greenness (an indicator of leaf chlorophyll content) using a handheld SPAD-502 (SPAD) optical sensor, and also measured plant height. Both polarization and leaf greenness observations at the heading stage were able to distinguish the canopies that had received topdressing from those without topdressing. However, no significant correlation was observed between the polarization in the blue, green and red bands and the SPAD (r = 0.425?0.456, n = 12 observations, p < 0.05). On the other hand, the mean leaf inclination angle (= mean tip angle: MTA) measured by the LAI-2000 was inversely correlated with the polarization in the 3 visible bands (r = ?0.85??0.88, n = 12, p < 0.001). Adjusting the view zenith angle according to the solar position at the time of measurement improved the accuracy. We tested a linear regression model to predict the MTA of the two wheat varieties based on polarized reflectance in the red band centered at 660 nm (r ² = 0.73, n = 12, p < 0.001). Validation of this model obtained in the subsequent cropping season confirmed that polarization measurements were potentially useful for estimating the MTA of wheat stands in which the panicles were located below the topmost leaf layer of the canopy.     

Evaluation of the SPAD Value in Faba Bean (Vicia fabaL.) Leaves in Relation to Different Fertilizer Applications

Abstract

The correlations of the reading of a portable chlorophyll meter (SPAD-502) with the chlorophyll and N contents of leaves of two faba bean (Vicia fabaL.) cultivars, Japanese (Ryousai-issun) and Egyptian (Cairo 241), were examined. The SPAD readings positively correlated (ρ<0.01) with the chlorophyll contents and the r² values were 0.99 and 1.00 for Ryousai-issun and Cairo 241, respectively. A close linear relationship (ρ0.001) was observed between SPAD reading and total leaf N content at the pod development stage of faba bean plants with r² = 0.88 and 0.99 for Ryousai-issun and Cairo 241, respectively. The SPAD reading was the highest in the 2^nd to 4^th leaves counted from the top (the youngest fully expanded leaves). The changes in leaf chlorophyll content of both cultivars from 3 weeks after transplanting to the ripening stage showed an incomplete “M” type curve. SPAD readings were significant¬ly higher in Ryousai-issun than in Cairo 241 throughout the growth season. Organic fertilizers application improved faba bean plant growth. These results suggest that the SPAD-502 chlorophyll meter can be used to measure chlorophyll and nitrogen contents of faba bean leaves for quick screening faba bean genotypes.