套袋时期对‘立冬本’龙眼果实生长发育和品质的影响

以福建省晚熟龙眼品种'立冬本'果实为材料,研究果实采前套袋时期(盛花后80、95、110d)对龙眼果实生长发育、外观品质及果肉内在品质的影响.结果表明:果实采前套袋时期越早,则落果率越高;果实采前3个不同套袋时期都可以增加果实纵径、横径和单果重,提高果皮叶绿素、类胡萝卜素、花色素苷和类黄酮含量,以及果肉的可溶性固形物、总糖、维生素C和可溶性蛋白质等营养物质含量,降低可滴定酸含量.综合研究结果认为.'立冬本'龙眼果实的最佳套袋时期为盛花后110d.即果实采收前1个月左右.     

芍药蕾期叶片SPAD值与净光合速率的变化

以2个芍药品种大富贵与红艳争辉为材料,测定了芍药蕾期不同叶位叶面积、叶片SPAD值、净光合速率(Pn)。结果表明,现蕾初期叶面积从大到小依次为基部、中部、顶部,至现蕾末期,以中部叶面积最大;不同叶位的叶面积随着花蕾的发育不断增大,现蕾30 d叶面积达到最大,约为现蕾初期的3倍;不同叶位叶片的SPAD值在蕾后10 d迅速增大,之后增加幅度降低,大富贵高于红艳争辉;现蕾初期叶位越高,SPAD值越低;不同叶位叶片的Pn值随着生长发育均呈直线上升趋势,蕾后30 d的Pn值约为现蕾初期的3倍,大富贵的Pn值高于红艳争辉,不同叶位叶片的Pn值与SPAD值呈显著正相关。     

青菜豆2号不同生育期光合生理指标对产量的影响

为明确矮秧菜豆不同生育期光合生理指标对产量的影响,以矮秧菜豆新品种青菜豆2号为试验材料,对其不同生育期光合生理指标进行了测定。结果表明,3个生育期中,净光合速率(Pn)与蒸腾速率(Tr)在青熟期达到最大,从苗期至花荚期,胞间二氧化碳浓度(Ci)与气孔导度(Gs)同步减小,表明此阶段光合速率主要受气孔限制,而从花荚期到青熟期,Ci随着Gs的增大而减小,此阶段光合作用的主要限制因素属非气孔因素,即叶肉细胞光合活性增加,CO2同化能力降低,也是叶片羧化活性不同的反映。通过对青菜豆2号不同生育期光合生理指标与产量的关联性分析得出,苗期各光合生理指标对产量的关联性均表现为最高,而青熟期各光合生理指标的关联性表现较低。     

海阳市冬小麦生长期的气候条件分析

应用海阳市近50年的气温、降水、日照等气象资料和出现的气象灾害记录资料,分析了海阳市冬小麦生长期的气候条件,指出了影响冬小麦生长的干旱、连阴雨、冰雹、晚霜冻等不利气象条件发生的频率及出现的天气形势,并提出了相应的防御措施.     

太阳系天体相对地球某点的波动式螺线运动(Ⅱ)——太阳系七大行星相对地球某点的螺线运动方程推导及模拟分析

为研究太阳系天体相对地球某点的运动规律,在太阳系天体相对地球某点的波动式螺线运动(I)中推导出太阳和月球对地球赤道某点和纬度某点的波动式螺线运动轨迹方程,并进行了计算机模拟与分析的基础上,推导出太阳系七大行星对地球赤道某点和纬度某点的波动式螺线运动轨迹方程,并分别进行了计算机模拟与分析.结果表明,太阳系七大行星相对于地球某点的运动轨迹为与幅值与角度相关的波动式螺线,向x轴方向等速传播,并且在两种坐标轴下的运动规律与太阳、月亮类似.并且:1在双波动坐标轴下分析,水星运动轨迹在yz平面上的投影出现重波;2金星运动轨迹在yz平面上的投影疏密度与其余星球相反;3在波动-螺面坐标轴下分析,天王星和海王星螺线与太阳的最相近.     

单季杂交中稻新品种比较试验

采用单因素随机区组设计,以丰两优四号作对照,对引进的12个杂交中稻新品种进行品比试验,结果表明:荟丰优3518和广两优1393分别比对照增产21.55%和19.78%,增产均达显著水平,且综合性状好,可继续扩大示范种植。     

渗灌在日光温室樱桃番茄上的应用效果研究

以樱桃番茄为试材,在日光温室内研究了渗灌对樱桃番茄生育期、产量、品质和用水量的影响.结果表明:渗灌可有效提高樱桃番茄产量和改善果实品质,并降低用水量.渗灌条件下,樱桃番茄提前上市5 d,用水量比膜下灌溉少10.96%,水分生产率提高5.61 kg/m3;产量提高2878.5 kg/hm2,平均单果重提高1.5989 g,可溶性固形物含量提高0.365%.     

外源ABA对苗期低温下冬小麦蔗糖含量及其关键酶基因表达的影响

为了探讨外源ABA对苗期低温下冬小麦植株蔗糖代谢的调节作用,以抗寒性强的品种东农冬麦1号和抗寒性弱的品种济麦22为试验材料,在三叶期分别于不同温度下经ABA处理48 h后取叶片和地下茎,研究外源ABA对苗期低温下冬小麦的蔗糖含量及蔗糖代谢相关酶基因表达的影响。结果表明,外源ABA处理使低温下抗寒性强的东农冬麦1号中积累了更多的蔗糖,尤其是叶片,而在济麦22中则抑制了蔗糖的积累。4℃以上温度时,外源ABA促进了东农冬麦1号叶片和地下茎中UGP在蔗糖合成中的作用;在4℃以下低温时,外源ABA则促进了UGP在蔗糖分解中的作用。4℃以上温度时,外源ABA提高了东农冬麦1号叶片中Ta SPS基因和地下茎中Ta SAInv基因的表达,而抑制了济麦22各器官中Ta SPS基因和Ta SAInv基因的表达。此外,4℃以上温度时,外源ABA抑制了两个小麦品种各器官中Ta SS基因的表达。表明抗寒性强的东农冬麦1号对外源ABA可能更加敏感,其蔗糖合成能力的提高将有利于冬小麦植株抵御低温,进而维持植株的存活。     

Critical period for grain number establishment of near isogenic lines of two- and six-rowed barley

In barley no studies have attempted to pinpoint the critical period for grain number determination, and it is frequently stated that the critical period is similar to that of wheat. However, there are important differences between the species and among barley genotypes (i.e. two- and six-rowed types) suggesting that this assumption requires testing. The objectives of this paper were (i) to determine the critical period for grain number determination in two- and six-rowed barleys, and (ii) to identify which yield components were more sensitive to changes in incident radiation during that period.

Two field experiments were conducted using two pairs of near isogenic lines differing only in the spike type. Shading was imposed at different periods throughout the crop cycle (from 60 days before heading to 15 days after) to reduce incident solar radiation approximately 70%.

The critical period for grain number determination tended to be slightly earlier in two- (ca. between 40 and 10 days before heading) than in six-rowed barleys (ca. between 30 days before heading until that stage). In terms of the external phenology, the beginning of the critical period for setting grains was 10 days after the beginning of stem elongation, and 10 days before flag leaf appearance in two- and six-rowed lines, respectively. Changes in the number of grains per unit area were correlated with crop growth rate during the critical period for yield determination.     

Seed potato quality as influenced by high temperatures during the growth period. 2. Sprouting pattern in several cultivars in response to storage temperature

Summary Locally grown seed tubers of nine varieties developing in spring or in autumn in a semi-arid region were examined for length of dormancy and for sprouting response. In spring, high temperatures during the last part of tuber development markedly shortened the dormant periods of tubers in comparison with tubers of the same varieties developing in autumn. The sprouting behaviour of tubers indicated that it is a varietal characteristic influenced by the change in environmental conditions during tuber development and storage. On tubers developing in spring and stored at high temperatures, three sprouting patterns were defined: a) apical dominance, characterized by the evident development of the apical sprout and less than 10% sprouting of the non-apical buds; b) apical influence, the apical sprout well developed and 10–20% sprouting of the non-apical buds; and c) simultaneous sprouting of 3 or 4 sprouts of similar size per tuber. It is suggested that apical dominance is a relative rather than an absolute phenomenon. The extent of dominance depends upon the variety's response to the high temperatures during tuber growth and storage. Contribution from the Agricultural Research Organization, Beit Dagan, Israel, 1979 Series, No 301.