Summary: Middle‐aged women with a substantiated diagnosis of schizophrenia from Victorian Psychiatric Hospitals were examined for clinical, radiological and serological evidence of rheumatoid arthritis. Clinical or radiological evidence of rheumatoid arthritis was detected in none of the 301 patients studied, where‐as the expected prevalences would be 7.7%; this difference is highly significant (p < 0.001). On the other hand, the prevalence of serologically demonstrable rheumatoid factor in the women with schizophrenia was similar to that in subnormal women in hospital under the same conditions and in women from a normal Australian population. The demonstrable polarity of schizophrenia and clinical rheumatoid arthritis in women might be explained either on a genetic basis or through the “protective” effects of one disease, schizophrenia, on the occurrence of the other, rheumatoid arthritis.

A study has been made of a Mexican semi-dwarf wheat (Lerma Rojo X Norim 10- Brevor 14) Andes3, local accession number WW 15. In 53 trials, over two seasons and a wide range of conditions, this has shown a marked grain yield superiority over other Mexican and Australian varieties when grown in high yielding environments. Nine varieties in five trials were sampled at maturity. Varietal grain yield was highly correlated with harvest index and with the number of grains set relative to straw and chaff weight. WW 15 excelled in both ratios, and combined a dense ear population with many grains per ear.

The 49 cultivars in the Fifth International Spring Wheat Yield Nursery (ISWYN) were grown as single plants in pots and 16 characters measured. Grain yield of the cultivars as single plants was not significantly correlated with ISWYN mean grain yields, although there were high correlations between single-plant and field performance in days to ear emergence, height, and 100-grain weight. ISWYN cultivar mean yields were used as the dependent variable in a stepwise regression analysis with the 16 single-plant characters as the independent variables. Harvest index accounted for 71.7% of the variability in ISWYN yields, and days to emergence of leaf 7 and 100-grain weight raised this to 78.5 % in a multiple regression. These results suggest a new, indirect method of predicting relative mean yields of wheat genotypes.

Because of the expected importance of photosynthetic activity to yield, the relationships of leaf photosynthetic traits to crop growth rate and yield in 48 genotypes of spring wheat, were examined under irrigation in northwest Mexico. There were three tall and 33 short (Norin 10-derived) bread wheats (Triticum aestivum L.), eight short durum wheats (T. turgidum L.) and four triticales (X Tritosecale Wittmack). Photosynthetic activity (A) and leaf permeability viscous air flow (LP) were measured weekly using 14CO, uptake and an air flow porometer, respectively.Genotypic effects on A (range 14.7 to 20.4 mg dm-* hour -*) and LP (range 5.7 to 11.1 permeability units) were highly significant but species effects were small and nonsignificant. Looking now exclusively at the short bread wheat group, A was unrelated to specific leaf weight or to LP A on the first sampling at 4 weeks before anthesis and preanthesis crop growth rate (g -z day-*) were weakly c orrelated ( phenotypic r = 0.42, significant at the 0.05 level), and both these traits were positively correlated with mature plant height (r = 0.56, significant at the 0.01 level, and 0.68, significant at the 0.05 level, respectively). A was also positively correlated with crop growth rate during grain filling (r = 0.46, significant at the 0.01 level) and with yield (r = 0.45, significant at the 0.01 level; yield range 516 to 860 g m-Z). These correlations arose because of the positive influence of days to anthesis on all three traits and probably reflect an increase in sink size (more kernels -z) with l ater a nthesis. Y ield w as positively correlated with LP (r = 0.56, significant at the 0.01 level); the correlations remained significant (r = 0.46, significant at the 0.01 level) after allowance for the negative effect of plant height on both (LP was unrelated to anthesis date). While the cause of this correlation may be indirect, the testing of LP as an early generation selection criterion is suggested. Effects of major Norin 10 dwarfing genes on these relationships are discussed.

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