A transformation system was developed for the commercial apple (Malus X domestica Borkh.) cultivar Royal Gala. Leaf pieces from in vitro-grown shoots were cocultivated for 2 days with Agrobacterium tumefaciens strain LBA4404 containing the binary vectors pKIWI105 or pKIWI110. Shoots were produced on a shooting medium containing kanamycin (50 mg·L(-1)). A 2-day incubation period on kanamycin-free medium prior to antibiotic selection enhanced the regeneration of kanamycin-resistant shoots. The majority of the kanamycin-resistant shoots also expressed GUS (β-glucuronidase) activity. The putatively transformed shoots were rooted on a medium containing kanamycin (50 mg·L(-1)). Rooted plants were established in a greenhouse, and plants transformed with pKIWI110, which contains a mutant Arabidopsis acetolactate synthase gene, were shown to be resistant to the herbicide Glean(™). Integration of T-DNA into the apple genome was confirmed by PCR and Southern hybridization analyses.

Neotyphodium lolii is a fungal endosymbiont of the ryegrass Lolium perenne. Its growth is tightly controlled and synchronized with that of the plant. How the symbionts communicate is largely unknown but failure of the endophyte to elicit a defense response is considered crucial for successful symbiosis. In silver-stained two-dimensional gels of protein extracts from endophyte-infected ryegrass, a fungal Cu/Zn superoxide dismutase was detectable, even though the fungus accounts for only <¹/500 of the biomass, indicating that it is an abundant fungal protein and that the fungus needs protection against reactive oxygen species. The plant increased levels of a pathogenesis-related class 10 (PR-10) protein; when equal amounts of protein from infected and uninfected plants were loaded, PR-10 was only detectable in extracts from infected plants. Presence of the endophyte did not lead to a significant increase in PR10 transcript levels. In protein extracts from a symbiosis containing an N. lolii variant with an abnormal in planta growth pattern, the fungal Cu/Zn superoxide dismutase but not PR-10 protein was detectable. The correlation between increased PR-10 levels and presence of a normally growing endophyte is suggestive of a role of a very limited host defense in the interaction between grass and endophyte.

SummaryIn many plant species, it has been demonstrated at the whole plant level that supplemental Ca 2+ alleviates the effects of salinity stress. These effects have been attributed to physiological processes, but there are no reports of the effects of supplemental Ca 2 § on preventing nuclear damage to the root meristematic cells following exposure to NaCI salinity. Two in vitro cultured potato (Solarium tuberosum L.) cultivars, analysed by fluorescent microscopy and flow cytometry, showed a similar pattern of salinity-induced changes to the nuclei of root meristematic cells. Damage occurring after only a few hours was followed by nuclear degradation at 24 h. Flow cytometry histograms showed a reduction in GI and G2 nuclei and an increase in degraded nuclei in NaCI-stressed roots. Salinity-induced nuclear degradation was alleviated by the addition of CaCI,.

Genetic changes in fibre characteristics of perennial ryegrass (Lolium perenne) may enhance degradability and thereby improve voluntary feed intake and energy availability from ingested grass.

Anthers from 32 genotypes from one line of annual ryegrass (Lolium multiflorum) and 229 genotypes from 15 cultivars of perennial ryegrass (L. perenne) were tested for the production of haploids and double haploids. Six (23%) annual and 71 (31%) perennial ryegrass genotypes produced calli ranging from 1.3-16% and 0.8- 12.2% respectively. However none of the annual ryegrass genotypes produced green plants and only one genotype (Option WH-1) of perennial ryegrass produced 16 (1.8%) green plants. The remaining produced only albino regenerates. Twelve of the 16 green plants were evaluated cytologically for chromosome numbers. Four were haploids thus confirming their origin from haploid pollen. The remaining eight were all diploids. One haploid and one diploid were tested for their homozygous condition using seven simple sequence repeat (SSR) markers and were found to be homozygous at all seven loci. In order to increase the recovery of green regenerates, we have used the responsive genotype Option WH-1 in crosses with three other perennial ryegrass genotypes and the progenies are currently been grown for anther culture