Hawaii as a Natural Laboratory for Research on Climate and Plant Response

The interplay of genetic and environmental forces has resulted in the process of evolution. The distribution of indigenous plants is a product of the genetic make-up of the successful invaders of a particular area and the total physical and biological environment of that area. Native plants have achieved a point in which their genetic constitution is in a certain degree of harmony with their environment. Plants in extreme latitudes, for example, have a genetic constitution which few, if any, tropical plants possess and so are able to withstand the low temperatures. The successful cultivation of economic plants is in even greater measure dependent upon the harmonious interaction of the plant's genes and its environment. One of the most important components of the plant's environment is climate

The effect of age and location of leaf on quantity and quality of japanese mint oil production

Leaves of debranched Japanese mint (Mentha arvensis L., subsp. haplocalyx Briquet var. piperascens Holmes) were marked to allow subsequent identification for age. Leaves of different age groups were distilled for determination of quantity and quality of oil. Most of the oil and its principal component, menthol, were synthesized during the first 2 weeks of growth, while menthone and the a-pinene percentage composition of the oil declined with age after 2 weeks. A significant decrease in percentage oil content occurred in older leaves indicating that leaf loss through senescence caused less loss of oil than of dry matter. Proportion of young to old leaves had a significant effect on oil composition. This is believed to be the first report on oil composition of leaves from single plants of Japanese mint

Pachytene chromosome identification by a key based on chromomeres in the pigeonpea

A method for the preparation and utilization of the pachytene chromosome karyotype of the pigeonpea is presented. Major chromomeres, most of which were compound structures, were used to characterize individual chromosomes. The karyotype was prepared from a large number of cells showing only one or a few analyzable chromosomes, rather than scarce cells showing the entire chromosome complement. As all 11 chromomere patterns were identified in each of two cells showing all 11 chromosomes clearly, this indicated that the entire genome had been described. A key, based on distribution and structure of major chromomeres, provides a rapid means of identification and comparison

Inversion heterozygosity in the hybrid soybean × Glycine soja: Evidence from a pachytene loop configuration and other meiotic irregularities

Meiotic irregularities and partial sterility were found in the hybrid between the soybean, Glycine max and its presumed wild progenitor, Glycine soja. Chromosome bridges and fragments were believed to be caused by inversion heterozygosity. The presence of an inversion was confirmed by finding an inversion loop at pachytene. Other evidence for inversions came from bivalents that failed to separate in the first division. These bivalents acted as laggards or passed intact to one pole at anaphase I. Nondisjunction of the partners in the bivalents was believed to result from chiasmata occurring in the region of an inversion in the bivalents. The number of bridges, fragments, and lagging bivalents suggest the presence of more than two inversion differences between the two species.Chromosomal differentiation together with wide genetical and morphological differences provide evidence that G. max and G .soja are two distinctly separate species

A semimicro apparatus for essential oil determination of multiple mint samples by steam distillation

An apparatus is described which allows simultaneous steam distillation of ten individual plants for essential oil determination. Volume of recovered oil can be read to 0.01 mL. Tests on mint oil for accuracy and reproducibility gave a mean recovery of 89.9 ± 1.1%. Yields of oil from plant of five species and varieties of mint (Mentha) ranged from 3.45 to 8.90%

Optimized Hybridization of DNA Blotted and Fixed to Nitrocellulose and Nylon Membranes

Seven nylon membranes were tested in different DNA transfer and post–transfer procedures. The sensitivity of the hybridization signals was increased ten–fold over conventional Southern blot analysis using nitrocellulose, by UV–irradiating DNA blotted to nylon membranes at high salt concentrations. This treatment also improved the sensitivity of the signals with nitrocellulose membranes. UV–irradiation of DNA transferred to nylon membranes in low salt buffers or alkali reduced hybridization efficiency