美国加利福尼亚州的芦笋生产(续上期)

由于加利福尼亚州南部沙漠和沿海地区的笋农希望密植,因此,常采用直播法建立芦笋园.土地准备:很多种植者象种其它中耕作物那样把芦笋种子直播在凸起的畦或平的地面上.但最好直播在专门预先作好的种植沟内,这样在以后的年份有充足的土壤可对植株培土并保证根颈埋于土表以下.通常采用的是平底沟间距5英尺,中心比原来的地面深5—7英寸.最初的沟用双壁犁开成,用装在橇上的畦成形器整畦,畦成形器后通常安装有精确的种植机,以便使畦的植距和种植作业操作一次完成.整好的畦在行间需有一平而坚实的埂以便于装备在田间的运行.     

竹笋业研究在我国的进展概况

中国竹类资源十分丰富.竹林面积占世界四分之一,约340万公顷,年产竹材700万吨,成为世界主要产竹产笋国,其食用和栽培竹笋从唐代以前开始,至今已有2500年历史,目前,我国的竹林面积、竹种数量和立竹储备已超过印度而跃居世界首位.“七·五”期间,国家对竹业投资两千多万元,安排竹业星火计划十余项,极大地促进了我国竹业研究工作的进展.     

龙眼采后生理变化及对B9的效应

<正> 龙眼是我国的名贵水果,福建莆田是我国龙眼的主产地之一.1984年我们对莆田的龙眼进行了果肉细胞透性、果实呼吸强度及乙烯释放量的测定.     

竹笋产品的开发利用

竹笋肉质肥嫩,清脆可口,味道鲜美,享有素食第一美称.传统上,群众认为竹笋营养价值不高.实际上,据分析,竹笋含有蛋白质、脂肪、糖类、有机酸、胡萝卜素、维生素B族及多种微量元素和无机盐;竹笋所含的游离氨基酸达18种之多,其中7种为人体必需氨基酸.     

芦笋育种的研究

芦笋从清朝末年就传入我国,至今东北与华北地区仍有野生植株.芦笋为雌雄异株植物,雄株开花时间比雌株早1个月左右,而且开花节位较低,雄株寿命也比较长;雄株光合作用产生的同化物比雌株高27%,雄株拟叶比     

波姬红无花果果干制作方法筛选

以新鲜波姬红无花果为原料,采用鼓风干燥、微波真空干燥和真空冷冻干燥等三种方法制作无花果果干,筛选出适宜的干燥方法,并进一步完成干燥的具体方案。试验表明,鼓风干燥、微波真空干燥不适宜进行波姬红无花果的干燥,真空冷冻干燥的效果最好,其中在冻干压力40 Pa,冻干温度65℃,冻干时间24 h的条件下可保持波姬红无花果固有色、香、味、形和营养成分。此外还对干燥前后的无花果的维生素C含量、可溶性糖含量和蛋白质含量进行了测定和对比。     

漳州市竹笋业现状及发展对策

本文主要论述漳州发展竹笋业的有利条件、漳州竹笋业的现状,提出今后发展漳州竹笋业的对策。     

Induction of anatomically based defense responses in stems of diverse conifers by methyl jasmonate: a phylogenetic perspective

Conifers have evolved constitutive and inducible defense mechanisms to help in both wound healing and defense against attack by bark beetles and other organisms. These defenses include oleoresin, phenolics, and static structures in secondary phloem, such as lignified cells and calcium oxalate crystals, that create physical barriers. We used a phylogenetic approach to investigate the defense anatomy of conifer stems of 13 species from five families following treatment with methyl jasmonate (MJ), a compound that induces defense responses in stems of several Pinaceae species. Methyl jasmonate induced a response similar to wounding except that the response was not accompanied by lesion formation, necrosis or a hypersensitive response. In the Pinaceae species studied, MJ induced polyphenolic parenchyma (PP) cell activation and xylem traumatic resin duct (TD) formation. Members of the Taxodiaceae, which are not known to produce large quantities of resin, showed massive xylem TD formation and surface resinosis following MJ treatment. Treatment with MJ caused members of the Araucariaceae and Cupressaceae to form axial phloem resin ducts but not xylem ducts, whereas Podocarpaceae species showed no induction of resin-producing structures. All species treated with MJ showed phenolic deposition in PP cells, and early lignification of phloem fibers was observed in most of the non-Pinaceae species. We conclude that, although evolution of resin-producing structures occurred independently in conifer lineages, MJ seems to induce resin production regardless of tissue location, as well as inducing deposition of phenolic compounds. Co-evolution of conifer defensive strategies and bark beetle pests is discussed.     

The last deglaciation of the southeastern sector of the Scandinavian ice sheet

The Scandinavian Ice Sheet (SIS) was an important component of the global ice sheet system during the last glaciation, but the timing of its growth to or retreat from its maximum extent remains poorly known. We used 115 cosmogenic beryllium-10 ages and 70 radiocarbon ages to constrain the timing of three substantial ice-margin fluctuations of the SIS between 25,000 and 12,000 years before the present. The age of initial deglaciation indicates that the SIS may have contributed to an abrupt rise in global sea level. Subsequent ice-margin fluctuations identify opposite mass-balance responses to North Atlantic climate change, indicating differing ice-sheet sensitivities to mean climate state.