Survival of four accessions of Anigozanthos manglesii (haemodoraceae) seeds following exposure to liquid nitrogen.

This study investigated the survival of seeds from the prominent endemic Western Australian species Anigozanthos manglesii following exposure to liquid nitrogen (cryostorage). Seeds from four different accessions (collected in 1987, 1990, 1993 and 1998) adjusted to different water contents were tested for survival following cryostorage. Water content was a significant determining factor with survival of cryostored seeds declining rapidly at water contents above c.

Cryopreservation of the australian species Macropidia fuliginosa (Haemodoraceae) by vitrification.

Somatic embryos were used to develop a cryopreservation protocol for Macropidia fuliginosa, a commercially-important species endemic to the south-west of Western Australia. Somatic embryos were allowed to develop from embryogenic callus for three weeks on an kinetin medium prior to processing. These were transferred and cultured on a agar solidified basal medium supplemented with 0 to 0.

Effects of plant growth regulators on survival and recovery growth following cryopreservation.

Studies on the effects of plant growth regulators (PGRs) on survival, recovery and post-recovery growth of shoot apices following cryopreservation are limited. In this study, the effects of plant growth regulators in both the culture phase and the recovery phase of cryostorage were examined for the rare plant species, Anigozanthos viridis ssp terraspectans Hopper. Survival of shoot apices was not correlated to cytokinin or auxin treatments administered in culture media prior to cryostorage.

Stereochemical arrangement of hydroxyl groups in sugar and polyalcohol molecules as an important factor in effective cryopreservation.

The efficacy of several sugars and polyalcohols in preculture medium was investigated using Anigozanthos viridis ssp terraspectans Hopper (Haemodoraceae), a threatened plant species endemic to the south west of Western Australia. A vitrification protocol involving preculturing of shoot apices for 3 days on different concentrations of sugars and polyalcohols, followed by incubation in plant vitrification solution 2 (PVS2) for 25 min, prior to immersion in liquid nitrogen (LN) and warming resulted in shoot tip survival ranging from 34 to 84%. High levels of survival were obtained with polyalcohols, compared to sucrose, glucose, trehalose and raffinose when used at the same molarity (0.

Significance of the zygotic seed coat on quiescence and desiccation tolerance of Medicago sativa L. somatic embryos.

The influence of the zygotic seed coat on precocious germination and desiccation tolerance of somatic embryos has been studied using alfalfa (Medicago sativa L.). When cultured in contact with somatic embryos, seed coats at certain developmental stages inhibited precocious germination and induced desiccation tolerance in the somatic embryos.

Somatic embryogenesis and plant regeneration from zygotic embryo culture in blue spruce (Picea pungens Engelman.).

Somatic embryogenesis and plantlet formation have been achieved from cultured mature zygotic embryos of blue spruce (Picea pungens Engelman.). The effect of three basal media LP, LM, and BLG, all used at half-strength, was tested at the induction phase.

Artificial seeds.

The use of somatic embryos as artificial seeds for large scale clonal propagation of plants is close to becoming a reality. The quality of the artificial seed depends on the temporal, quantitative and qualitative supply of growth regulator and nutrients along with an optimal physical environment. Desiccation of somatic embryos provides a quiescent phase analogous to true seeds, facilitating the convenience of year round production, storage and distribution.

Desiccation of microspore derived embryos of oilseed rape (Brassica napus L.).

Microspore-derived embryos from Brassica napus L. were dried to less than 15% moisture and stored dry for a minimum of 7 days. Successful plant regeneration was observed when embryos at the cotyledonary stage of development were treated with 50 uM ABA for 7 days prior to desiccation.

Growth, ammonia accumulation and glutamine synthetase activity in alfalfa (Medicago sativa L.) shoots and cell cultures treated with phosphinothricin.

Phosphinothricin is a non-selective herbicide which inhibits glutamine synthetase (EC 6.3.1.

Antioxidant levels in germinating soybean seed axes in relation to free radical and dehydration tolerance.

The axis of soybean seeds suffer dehydration injury if they are dried to 10% moisture at 36 hours of imbibition, but tolerate this stress if dried at 6 hours of imbibition. Deesterification of membrane phospholipids has been correlated with the increased permeability and increased lipid phase transition temperatures of membranes from dehydration injured tissues. Deesterification, measured as increased free fatty acid:phospholipid and decreased phospholipid:sterol ratios, occurred primarily when the tissue was in the dry state and did not change significantly (P View Article and Find Full Text PDF

Simulation of dehydration injury to membranes from soybean axes by free radicals.

Smooth microsomal membranes were isolated from axes of soybean (Glycine max L. Merr.) seeds at the dehydration-tolerant (6 hours of imbibition) and dehydration-susceptible (36 hours of imbibition) stages of development and were exposed to free radicals in vitro using xanthine-xanthine oxidase as a free radical source.

Association between Membrane Phase Properties and Dehydration Injury in Soybean Axes.

Axes of soybean seeds are tolerant to dehydration at 6 hours of imbibition, but susceptible to dehydration injury if dried at 36 hours of imbibition. Smooth microsomal membranes were isolated from axes imbibed for 6 hours (dehydration tolerant state) and 36 hours (dehydration susceptible state) before and after dehydration treatment. The phase properties and the lipid composition of the membrane fraction were investigated.

Characterization of Solute Efflux from Dehydration Injured Soybean (Glycine max L. Merr) Seeds.

Soybean (Glycine max L. Merr) seeds lose their tolerance of dehydration between 6 and 36 hours of imbibition. Soybean axes and cotyledons were excised 6 hours (tolerant of dehydration) and 36 hours (susceptible) after commencing imbibition and subsequently dehydrated to 10% moisture.

Dehydration Injury in Germinating Soybean (Glycine max L. Merr.) Seeds.

The sensitivity of soybean (Glycine max L. Merr. cv Maple Arrow) seeds to dehydration changed during germination.