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A KNOWLEDGE of the genetics of resistance to leaf •*"*• rust of wheat, Triticum aestivum L., caused by the rust organism Puccinia recondita Rob. ex. Desm., would greatly reduce the empiricism involved in practical rust breeding programs and hasten production of resistant varieties. Breeding for leaf rust resistance is complicated by the occurrence of many physiologic races of the causal organism. A total of 183 physiologic races has been registered by Johnston (8). Investigations reported here were undertaken to identify by monosomic analysis the chromosomes of the eight leaf rust differential varieties that carry the gene or genes for resistance to races 9 and 15 of leaf rust. Those two physiologic races are the most common races in Kansas. REVIEW OF LITERATURE Chester (4) reviewed early studies of inheritance of leaf rust resistance in common wheat and found that, in general, leaf rust resistance was inherited in a simple Mendelian .fashion, when hybrids from pure lines of wheat were tested for reaction to pure rust races. Soliman et al.

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Acacia farnesiana (L.) Willd. is a very important multipurpose species in Egypt and many other countries. It is valued as forestry and as an ornamental tree. Its flowers produce a perfume called " cassie " extensively used in European perfumery. The present study aims to the determination of the effect of helium-Neon (He-Ne) light irradiation on accelerating the germination of A. farnesiana seeds, which have dormancy due to impermeability of seed coat of water. The seeds were exposed to He-Ne laser light for 1, 3, 5, 7, and 9 minutes with different irradiance 0.03, 0.20, 0.61, 1.14, and 1.70 W/cm 2. Gibberellic acid (GA), indole-acetic acid (IAA), abscisic acid (ABA) as well as phenols were determined after 48h in treated and untreated seeds. Thin sections in the testa were also made. Germination indices: the time to germinate, germination period, germination percentage and germination speed were determined. The results showed that irradiation by the laser beam of the seed coat, (testa or pericarp, the envelope enclosing the seed embryo), succeeded in perforating the seed coat at one or more positions. Generally, an increase in irradiance and exposure time of He-Ne laser light irradiation increased levels of endogenous promoting substances (GA and IAA), and decreased levels of endogenous inhibiting substances (ABA and phenol) in seed coats. We conclude that irradiance of seeds with He-Ne laser light at 1.70 W/cm 2 for 9 min. significantly affected germination indices when compared with control seeds.