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- Author or Editor: Paul M. Hasegawa x
- HortScience x
Abstract
Cultured shoot tips and lateral buds from greenhouse-grown rose (Rosa hybrida L. cv. Improved Blaze) proliferated multiple shoots on a basal medium (MS salts, vitamins, glycine, sucrose, and agar) supplemented with 3.0 mg/liter 6-benzylamino purine (BA) and 0.3 mg/liter indoleacetic acid (IAA). A 3-fold multiplication was achieved from freshly explanted terminal shoot tips or lateral buds after 8 weeks. Reculture of in vitro-derived shoots onto the same medium resulted in a 6-fold increase in 8 weeks. Roots could be initiated from about 50% of these shoots after transfer to a medium containing 0.3 mg/liter IAA and 0 or 0.3 mg/liter BA. Regenerated plants were successfully transferred to soil after 2 weeks.
Abstract
Callus was initiated from cultured immature inflorescences of Hosta plantaginea Asch. ‘Grandiflora’ in darkness on a basal medium containing Murashige and Skoog salts, vitamins, glycine, i-inositol, sucrose, agar, and 10 mg/liter naphthaleneacetic acid (NAA) and 0.1 mg/liter 6-benzylamino purine (BA). Reculture of the callus onto a medium containing 0.01 mg/liter NAA and 5 mg/liter BA, resulted in the formation of numerous adventitious shoots. Adventitious shoots were initiated also from leaves and segments of leaves from shoots formed in vitro when cultured on a medium supplemented with 0.01-1 mg/liter NAA and 5 mg/liter BA. Root formation was achieved when individual shoots were excised and transferred to a medium containing the basal constituents without growth regulator supplements. Rooted plants were successfully transferred to soil.
Abstract
Adventive embryos of ‘Golden Delicious’ apple (Malus domestica Borkh.), with differentiated cotyledons and axes, were initiated from micropylar halves of nucellus cultured in darkness on Murashige and Skoog’s salts, vitamins, glycine, and sucrose. Embryos were observed 50 days after culture. Reculture of embryos onto the same medium resulted in proliferation of embryo-like structures from their cotyledons.
Abstract
In the paper “Stimulation of Root Initiation from Cultured Rose Shoots through the Use of Reduced Concentrations of Mineral Salts” by Scott E. Hyndman, Paul M. Hasegawa, and Ray A. Bressan (HortScience 17(l):82–83.1982) figures 1 and 2 were mis-positioned on the page. The correct placement of the figures, along with their captions, appears below.
Abstract
In vitro-derived shoots of ‘Improved Blaze’ rose (Rosa hybrida L.) were used to investigate the cause of improved root initiation obtained by lowering the concentration of the Murashige and Skoog (MS) salt formulation in the nutrient medium. The number and length of roots per explant increased as the concentration of total nitrogen in the MS salt formulation was reduced from 60 to 7.5 mm. There was no effect on rooting with as much as a 16-fold reduction in the concentration of the remaining MS salts from that of the normal MS formulation, when total nitrogen was kept at a constant 7.5 mm. When nitrogen was maintained at 7.5 mm and the concentrations of the remaining salts were maintained at 1/2 times that of the MS salt formulation, rooting was unaffected by raising the total solute concentration with NaCl to that when the medium contained the full MS nitrogen salt complement. These results show that lowering the total mineral salt level in the nutrient medium provides a more favorable nitrogen salts concentration for rhizogenesis than that provided by the MS salt formulation.
Abstract
Salinity is a significant limiting factor to agricultural productivity, impacting about 9 × 108 ha of the land surface on the earth, an area about 3 times greater than all of the land that is presently irrigated (17, 18). Reduced productivity occurs as a result of decreased yields on land that is presently cultivated [about one-third of all irrigated land is considered to be affected by salt (18, 45)], as well as due to the restriction of significant agricultural expansion into areas that presently are not cultivated. In the United States, salinity is a major limiting factor to agricultural productivity, and as the quality of irrigation water continues to decline this problem will become more acute (1, 56). About 1.8 million ha of land are salt-affected in California (56), the major agricultural state in the nation. Annual losses to crop production in the salt-affected areas, including the Imperial, Coachella, and San Joaquin valleys, are substantial and are increasing at a significant rate each year (56).
Abstract
Water availability is one of the principal environmental limitations of crop productivity throughout the world. The water deficits, which are a consequence of either continuous or transitory periods of drought, cause significant yield reductions on presently cultivated land, and greatly restrict the cultivation of crops on over one-third of the earth’s land surface considered to be arid or semiarid (25). These restrictions on yield potential are rapidly becom ing of great concern in the face of the food demands of an ever increasing world population. The problem becomes complicated further by the fact that supplies of suitable irrigation water are dwindling rapidly, and that the costs of irrigation are becoming prohibitive. As a result, studies on the effects of water stress on plant survival and yield are attracting added interest in plant science research.