Investigations on Simarouba glauca Dc. in El Salvador

The use of the kernels of Simarouba glauca as a potential source of vegetable oil was first noted in 1939. These kernels produce 62 per cent edible oil under commercial extraction procedures. The trees are polygamo-dioecious, thus creating a selection problem for commercial plantings. A progress report of investigations on the botany, propagation, selection, insect pests, and diseases is given.

     

Palm Chromosome Studies Facilitated by Pollen Culture on a Colchicine-Lactose Medium

This technique is very useful where pollen is readily available and when roots or microspore mother cells are difficult to obtain or to process. It provides a relatively uniform means of studying chromosomes in a great number of species. Pollen is collected from buds at anthesis or the day before and sown on a medium containing H₃BO₃, 100 ppm; colchicine, 0.04%; lactose, 12%; gelatin, 5%; egg albumen, 1 drop in 10 ml. The gametic chromosome complement is studied at mitosis of the generative cell in the pollen tube. In species which have sufficiently large chromosomes it is possible to construct idiograms for comparative studies. All palm species here reported have a haploid complement of n = 18, and the chromosomes range in length from 0.5-3.5 μ.