Inheritance studies of characters associated with floating habit and their linkage relationship in rice

Summary Deep water rice varieties in general have certain peculiar characters which are associated with floating habit. These characters are (i) early nodal differentiation, (ii) nodal rooting, (iii) spreading habit, (iv) awned grains, (v) brown hull colour, (vi) red pericarp (red rice), and (vii) seed dormancy. Inheritance of these characters and linkage relationship of genes governing these characters were studied in a cross between Pankaj (non floating) and Nageribao (floating) rice varieties. Nageribao, a cultivar from Assam possesses these characters.Early nodal differentiation was observed to be controlled by a single dominant gene, designated as Nd. Nodal rooting was controlled by two dominant complementary genes, designated as Nr ₁ and Nr ₂. We found an inhibitory factor for spreading habit and one for brown hull colour in Pankaj; the operation of two dominant duplicate genes An ₁ and An ₂ for controlling awning characters, a single dominant gene Rd for red pericarp colour and a single dominant gene Gd for grain dormancy. Joint segregations between these characters resulted in the assignment of genes in the X linkage group of indica rices with estimated map distances based on the cross-over values. The genes An (awning), Es (spreading habit), Nr (nodal rooting) and Nd (nodal differentiation) were observed to be associated with each other. The gene for red pericarp (Rd) was observed to be linked with the grain dormaney gene Gd.     

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.     

Inheritance of plant elongation ability at seedling stage in rice

Summary In a comparison of methods to study inheritance of plant elongation ability, 15-, 20-, 25-, 30-, and 35-day-old F₂ populations of a cross between Baisbish (floating variety) and IR42 (nonelongating semidwarf modern variety) of rice, (Oryza sativa L.) were subjected to 65 cm water depth for 7 days. Frequency distribution of plant height before and after submergence was obtained. Bimodal curves in 15-, 20- and 25-day-old populations gave good fits to 9:7 elongating: nonelongating plants, suggesting that elongation was due to two dominant complementary genes. Segregation in the 30-day-old population was not clear-cut. A seedling age of 20 days was subsequently chosen for further studies.Two F₂'s involving floating rice and a nonelongating semidwarf; four F₂'s involving floating rice and an elongating semidwarf; and two F₂'s involving elongating and nonelongating semidwarf parents were studied with 20-day-old seedlings in the same way. Floating rice combinations with nonelongating semidwarf parents as well as with elongating semidwarf parents segregated into 9:7 elongating: nonelongating ratio. It is possible that because elongating and nonelongating dwarf parents did not differ much in elongation ability at seedling age, their combination with floating rice parents provided similar segregation. The F₂ distributions for height in elongating and nonelongating dwarf cross combinations were continuous with one peak.Genetic constitution of parents proposed are Sd1 Sd1 El El for floating parents, sd1 sd1 El El for semidwarf elongating, and sd1 sd1 el el for dwarf nonelongating.     

湘中、南烤烟漂浮育苗技术研究及推广应用

为配合烤烟漂浮育苗技术在湖南的推广应用,针对当地实际,对漂浮育苗基质配方、肥料配方及漂浮育苗配套技术进行了研究。研究结果表明,由泥炭、炭化谷壳和珍珠岩按一定比例配成的14号基质较好的协调了基质中固、液、气的比例,适于漂浮育苗;漂浮育苗专用肥配方2充分利用水源中的钙镁等矿质成分,降低了生产成本,有利于漂浮育苗的推广应用;12月中旬是湘中、南烟区适宜的播期,能满足烟株120d以上的大田生育期和避免与后茬作物争季节的矛盾;剪叶3￣5次、剪叶面为1/3￣1/2烟叶面,有利于烟苗素质的提高;生产示范和推广应用表明,在育苗成本、烟苗素质、经济性状和对病害的防治等方面,漂浮育苗较两段育苗有优势。     

内浮顶罐下沉浮盘的改造

为提高内浮顶罐浮盘的抗沉能力，将钢制浮盘改造为铝质浮盘，叙述了具体的施工步骤及实际应用中应注意的事项。实践证明此改造方案效果较佳，可供借鉴。     

生态浮床技术应用研究进展

近年来,随着工农业的发展,人类对水环境的破坏日益严重,全球出现水资源短缺的现象,如何有效利用水资源及将污废水处理回用已经成为摆在人们面前的头等大事.传统的物理、化学方法虽然理论基础比较扎实,但是在实际应用中出现了不少的问题,如投资大、难操作、产生二次污染等.为了解决这些问题,人们将目光转向了利用高等植物净化污水.生态浮床技术作为其中一种生物处理技术,已经被越来越多地用于治理富营养化水体.生态浮床以其独特的优点,通过植物根系的吸附和吸收作用,富集水中的N、P等元素,降解、富集其他有害无毒污染物,并以收获植物体的形式将其搬离水体,从而达到治理水体的目的,既保护了水生态环境,又带来了一定的经济效益.     

人工鱼礁的环境功能与集鱼效果

人工鱼礁是用于改善海域生态环境，建设渔场和增养殖场的人工设施。人工鱼礁投放到海中后，使周围海域的流、光、音、底质等非生物环境发生变化，这种变化又引起生物环境的变化，使水生生物量增大，从而形成良好的渔场或增养殖场，焦鱼效果也非常明显。本文作者综述了人工鱼礁的环境功能和焦鱼效果，并分析了今后人工鱼礁研究的发展趋势，特别是人工鱼礁在海洋生态环境改造方面的应用前景。     

替代烤烟漂浮育苗基质中草炭的试验研究*Ⅱ 基质中有机物料混配比例对烤烟漂浮育苗的影响

 以草炭、腐熟玉米秸、腐殖土为有机材料，珍珠岩、蛭石为无机材料的混配基质为材料，研究了不同有机物料配比对基质出苗率、烟苗生长发育以及烟苗成苗素质的影响，结果表明：（1）腐殖土和腐熟玉米秸的混配比例是影响该型基质综合育苗性能的主要因素，在试验设定的草炭水平下，基质的出苗率、烟苗苗色、烟苗生长速度与生长势以及烟苗成苗素质与腐殖土在基质中的添加比例成正比，与腐熟玉米秸的比例成反比；（2）该型基质中草炭的适宜混配比例是30%～40%（V），以40%为最佳；（3）草炭比例处于试验所设置的最低水平（10%，V）时，腐殖土+腐熟玉米秸为50%+20%的处理在基质出苗率和烟苗的生长发育以及烟苗的成苗素质方面与CK均不存在显著性差异，该处理对于本课题组正在进行的烤烟漂浮育苗替代草炭基质的研究工作具有一定的参考价值。     

木材真空-浮压干燥过程中自由水迁移特性

该文以马尾松为试验材料 ,通过对真空 浮压干燥中木材内部温度场、湿度场随压力浮动频率变化的试验研究 ,总结出木材在真空 浮压干燥过程中内部自由水迁移的基本规律 ,并对水分迁移的机制与驱动势进行了分析 .试验结果和理论分析显示 ,在真空 浮压干燥过程中自由水的输运由两部分完成 ,一部分为毛细管压力下液体的团块迁移 ;另一部分为在压力梯度下 ,由于压力波动而引起自由水的蒸发或沸腾后所产生的水蒸气的迁移 ,且后者在自由水的迁移过程中占主导地位 .