Immunological cross-reactivity of pathogenic Nocardia and related organisms.

Aerobic actinomycetes associated with various clinical conditions in man and animals were studied for their antigenic relationships along with related organisms. Culture filtrate antigens obtained from 16 species were tested by antigen-antibody crossed-immunoelectrophoresis and by agar gel double diffusion against rabbit antibodies to Nocardia asteroides, N. brasiliensis and N. caviae. Weak cross-reactivity was detected among the three, Nocardia species and Micropolyspora brevicatena, but no cross-reactivity was noted with antigens from any of the other species studied.     

I. Immunosurveillance and tumorigenesis in BALB/c mice—1. Early reactive state in mesenteric granulomas

The cellular immune response in BALB/c mice mesenteric granulomas (MG) was analysed by the means of functional ultrastructure and the assessment of the presence or absence of asynchronous plasma cells in situ.

Results from this study establish: (a) the sequential events involved in the genesis of the oil-induced granulomas, (b) the weak T-cellular immune response and the almost absence of these cells in mitosis, (c) the presence of asynchronous plasma cells of type II was found in mice Nos. 8, 9, 10 and 11 and they were considered to be plasma cell mutants of temporary type, to indicate the first step of this cell alienation in tumorigenesis, (d) the high ratio of peritoneal macrophages was found and connected with what is known about it in the literature. It was speculated that the supraoptimal presence of peritoneal macrophages could have been responsible for the appearance of plasma cell mutants and (e) four morphological types of macrophages have been found in this animal's oil-induced MG, representing different stages of the monocyte transformation in situ.     

Characterization of QEet.ocs-5A.1, a quantitative trait locus for ear emergence time on wheat chromosome 5AL

QEet.ocs‐5A.1, a quantitative trait locus controlling ear emergence time, has been detected on wheat chromosome 5AL using single chromosome recombinant lines (SCRs) developed from a cross between ‘Chinese Spring’ (CS) (‘Cappelle‐Desprez’ 5A) and CS (Triticum spelta 5A). This locus has little influence on grain yield and its components, and thus has breeding potential for changing ear emergence time without yield reduction. To characterize the phenotypic expression of QEet.ocs.1 and to test its interaction with the Vrn‐A1 gene for vernalization response, six near‐isogenic SCRs differing for these two gene regions were grown together with the parental controls under different vernalization and photoperiod regimes. The T. spelta allele of QEet.ocs.1 accelerated heading time when vernalization and photoperiod were satisfied, demonstrating that the function of this QTL is earliness per se. There was no interaction between Vrn‐A1 and QEet.ocs.1.     

葡萄调亏灌溉技术的研究现状与展望

围绕葡萄调亏灌溉技术的研究现状,对调亏灌溉的发展及其影响因素进行了系统地阐述,并就调亏灌溉对葡萄果实品质、产量、水分利用效率的影响作了探讨.提出在适当的时期对葡萄进行适宜的水分胁迫不仅能改善果实品质及维持甚至提高产量,而且也能提高水分利用效率.最后,分析总结了当前在葡萄调亏灌溉中存在的问题,并对葡萄调亏灌溉的发展趋势进行了展望,明确了葡萄调亏灌溉技术进一步研究的方向.     

Genetic variation in testcrosses of European maize inbreds for resistance to the European corn borer and relations to line per se performance

The European com borer (ECB) Ostrinia nubilalis H. is a major pest in World maize Zea mays L. production. Objectives of this study were to (1) investigate the genotypic variance and covariance in testcrosses of European flint and dent inbreds for ECB resistance and agronomic traits, and (2) estimate the correlation between line per se and testcross performance for ECB resistance traits. A total of 16 flint and 24 dent inbreds and their testcrosses with two testers from the opposite germplasm pool were evaluated in four and three German environments, respectively. Using artificial infestation with ECB larvae, resistance was assessed by damage rating of stalks, tunnel length in dissected stalks, and relative yield of infested plots compared with protected plots. Yield losses due to ECB damage in testcross hybrids amounted to 40%. Significant genotypic variances between flint and dent lines and high heritabilities were found for damage rating of stalks for both line per se and testcross performance. Heritabilities were low or intermediate for tunnel length and relative grain yield. Correlations between line per se and testcross performance were tight for the damage rating of stalks and moderate for tunnel length and relative yield in both flint and dent germplasm. For damage rating of stalks, per se performance of lines tested in a few environments can be used to predict their testcross performance. In contrast, assessment of testcross performance for tunnel length and relative yield requires evaluating testcrosses with several testers in multi-environment trials.