U.S. Economic Growth vs. Environmental Conditions

A widely-held belief is that stricter environmental regulations stifle economic growth. To determine empirically the effect of environmental conditions and policies on state-level per capita income growth, a Barro-type economic growth model was estimated for the years 1982 to 1991, which correspond to two consecutive troughs in the business cycle. States with better environmental conditions had significantly higher income growth rates during this period. At the same time, stricter environmental policies did not significantly depress income growth. Data used include recently developed, consistent measures of environmental policy and quality for individual states, as well as data from the 1980 U.S. Census and Bureau of Economic Analysis.     

Cytology of Phleum sp. affin. P. montanum C. Koch

Diploid, tetraploid, and hexaploid plants occurred in foreign plant introductions of P. sp. affin. P. montanum from Turkey and Iran. Within-progeny variations in polyploid levels indicate that divergent races occurred as interspersed but natural populations. One to six B-chromosomes of varying sizes in addition to the normal chromosome complement were present in some plants. Their behaviours appeared essentially similar to those recorded for other species. Certain of the plants examined exhibited cytological features similar to those observed in known hybrids. These included prophase pycnosis, stickiness, split metaphase I plates, unoriented chromosomes at M-1, and low levels of pollen stainability. These features were absent in microsporocytes of other plants. Low open-pollination seed set characterized all plants examined. This may be due to hybridity or possibly to response to ecological conditions of the new environment.Results of co-operative work of the Crops Research Division, A.R.S., U.S. Department of Agriculture, and the Wisconsin Agricultural Experiment Station, Madison, Wisconsin.Former Graduate Student, Department of Agronomy, Wisconsin Agricultural Experiment Station, and Geneticist, Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture.     

秈粳稻杂交育种研究

作者研究了秈粳杂种的生育特性及结实性等经济性状的遗传变异,认为以出穗期为主要指标进行选择,结合其他性状的变异动态,逐步确立优良系统,有助于提高选择的效率,和建立较为合理的杂交育种程序与方法。     

金铁锁总皂苷提取工艺研究

采用正交设计,以齐墩果酸为对照品,采用5%香草醛冰醋酸-高氯酸显色剂,以总皂苷提取率为指标来确定金铁锁的最佳提取工艺。结果表明,最佳提取工艺如下：提取温度为70℃、乙醇浓度为80%、提取时间90 min、料液比1:8,该方法成本低、结果稳定、重复性好。     

谢君魔芋染色体数目的观察研究

（云南农业大学魔芋研究所,云南昆明 650201）     

迷人杜鹃种子特性与萌发实验研究

测定了迷人杜鹃种子的千粒重、吸水率、种皮透水性和种皮抑制物质,并统计在不同的贮藏方式、不同光照条件和不同萌发温度的处理下迷人杜鹃的发芽率和发芽势,并对所得数据作方差分析与LSD检验,结果表明:迷人杜鹃种子细小,千粒重仅有0.171 g,种皮透水性良好,种皮没有抑制种萌发的物质.室温干藏种子的发芽率和发芽势最大.而低温贮藏不利于种子的萌发.迷人杜鹃种子在自然光暗交替的光照下发芽率更高,出苗更整齐.恒温有利于种子的萌发.     

Avena fatua L. subsp. fatua v. glabrata Peterm. subv. pseudo-basifixa Thell. as a source of crown rust resistance genes

Summary An accession of Avena fatua L. subsp. fatua v. glabrata Peterm. subv. pseudo-basifixa Thell. (A. fatua L. CS Sel. No. 1), collected in Czechoslovakia in 1971, was found to be resistant to a wide range of crown rust races. Analyses of crosses of this oat with cvs. Weikuss, Leanda, Mona, Rodney A, Rodney B, Rodney M, Dodge and K 316 indicated that the resistance of A. fatua CS Sel. No. 1 is conditioned by one recessive gene which is in interaction with one partially dominant gene with additive effect. The expression of rust reaction was affected by temperature. The crown rust resistance genes of A. fatua L. CS Sel. No. 1 were non-allelic with stem rust resistance genes Pg-2 (A) and Pg-4(B).