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XIAO Hui-hai WANG Wen-long 《中国水稻研究通报》2008,(3):209-214
Changxuan 3S, a thermo-sensitive genic male sterile (TGMS) rice line with eui gene, is derived from the TGMS rice line Pei'ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elongation of the TGMS line with eui gene, Changxuan 3S and its parent Pei'ai 64S were used to study the effects of temperature on panicle exsertion. At 24℃, the uppermost internode of Changxuan 3S elongated the fastest from the 4^th day before flowering to 0 day (flowering), being 2.1-fold as that of Pei'ai 64S, whereas it elongated slowly during the 12^th day to the 4^th day before flowering and the 1^st to the 3^rd day after flowering. The uppermost internode of Changxuan 3S exserted from the flag leaf sheath at 22℃, 24℃ and 26℃, and the length of elongated uppermost internode increased with the decreasing temperatures. At 28℃, though the panicles of Changxuan 3S were still enclosed in the leaf sheath, the degree of panicle enclosure was significantly lower compared with Pei'ai 64S. Cytological studies on Changxuan 3S showed that the uppermost internode elongation was attributed to the increase of cell number and cell elongation, and the latter was more significant. Moreover, the numbers of outermost and innermost parenchyma cells and the cell length of the uppermost internode reduced with the increasing temperatures. 相似文献
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A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice. 相似文献
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小叶丁香又名四季丁香,为木犀科丁香属落叶灌木。植株丛生,成熟树高1.0~1.5m,单叶对生,叶近圆形或卵圆形,基部楔形、圆形至阔楔形,叶片长2-3cm,3年生植株开花结实,圆锥花序密集,自侧芽生出,花紫红色,芳香,6月是开花盛期,常有秋季再次开花现象,蒴果披针形,常为镰刀状,10月上旬种子成熟。小叶丁香是阳性树种,耐寒、耐旱、耐贫瘠、耐轻盐碱,抗病虫害能力强。产于辽宁省、西北、华北及华中有分布,常生于石质山坡上,黑龙江省除黑河以北地区以外其它地区均可栽培。小叶丁香适宜于四旁绿化,也可丛植、片植于路旁、草坪、林缘,由于株形低矮、枝叶稠密、萌芽力强、耐修剪,多修剪成球形配置在草地景点或道路隔离带中,还可修剪成绿篱,用于分隔小区。如果带状栽植后不修剪,当花开时节,形成一条花带,景色迷人,近年来苗木市场小叶丁香供不应求,是城市绿化的优良、珍贵树种,前景效益可观。 相似文献
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六道木,属忍冬科,,六道木属,灌木。我国约有十个品种,小叶六道木、南方六道木等几个品种都适合做盆景材料,分布在中部、西南部至东南部。六道木树高一般1m-3m。叶卵形、叶片较小;花白色或粉红色;聚伞花序单生或组成圆锥花序;花冠钟状,花期较长:花谢后花萼可在枝头上留1至2个月,也很漂亮。 相似文献