Intergeneric hybrids were obtained between Sandersonia aurantiaca and Littonia modesta using ovule culture. The embryos were rescued by culturing 14 to 30 day old ovules. The ovules were cultured on modified KM medium for varying lengths of time until they germinated. After germination the embryo-derived-plantlets were transferred to modified growth regulator-free MS medium on which they developed tubers and became quiescent. The quiescent tubers could be successfully transferred to soil. The hybrid nature of both the putative Sandersonia × Littonia and the Littonia × Sandersonia hybrids was indicated by flow cytometry that showed the hybrid plants had a DNA content midway between that of the two parents. Mitotic and meiotic chromosome counts from S. aurantiaca, L. modesta and the hybrids gave chromosome numbers of (2n=) 24, 22 and 23 respectively. Morphological analyses of the leaves and flowers showed that the hybrids displayed features that were intermediate between both parents. Hybrids were male and female sterile. No morphological differences were observed between the two hybrids.

Interspecific hybrids between Limonium perezii and L. sinuatum were obtained using L. perezii as the female parent. The embryos which formed were rescued by culturing 12- to 16-day-old embryos within their ovules. The ovules containing the embryos were cultured on modified B5 medium and the embryos were later excised and re-plated onto fresh medium. The embryos grew for varying lengths of time eventually reaching lengths of up to 10 mm, before ceasing growth. At this point they died. Transfer to modified MS medium containing 3 mg l-1 TDZ for 24 hours induced callus growth in the embryo derived tissues from which shoots developed. These shoots were proliferated on modified MS medium containing IBA, BAP and GA3. Shoots transferred to modified MS medium with added IBA for 6 days initiated roots which continued development after transfer of the explants to modified growth-regulator-free MS medium. After a further 28 days the plantlets were transferred to soil. The hybrid nature of one of the embryo-derived plants was determined by flow cytometry and by examination of morphological features. The mean DNA contents of 2C nuclei from L. perezii, the hybrid and L. sinuatum were 8.69 pg, 7.59 pg and 6.42 pg, respectively. Mitotic and meiotic chromosome counts from L. perezii and L. sinuatum and their hybrid revealed that they had chromosome numbers of 14, 16 and 15, respectively. Morphological analyses of leaves and flowers showed that the hybrid displayed a number of features intermediate between both parents.

Interspecific hybrids between Limonium perigrinum and L. purpuratum were obtained using L, perigrinum as the female parent. No hybrids were produced by the reciprocal cross. Twelve- to 15-day-old embryos were rescued and cultured within their embryo sacs on modified B5 or KM medium. After two to three days the embryos were excised from their embryo sacs and re-plated on to fresh medium. When the embryo-derived plantlets had attained a length of 1 cm they were transferred to a modified MS medium containing BA and NAA for shoot proliferation. Plantlets were transferred to modified MS medium supplemented with IBA for 24 hours for root initiation then to a modified growth-regulator-free MS medium for root growth. After a further 28 days the plantlets were transferred to soil-less medium for acclimatisation. The hybrid characteristics of one of the 15 embryo-derived plants were determined by flow cytometry and by examination of morphological features. The mean DNA contents of 2C nuclei from L, perigrinum, the hybrid and L purpuratum were 13.98 pg, 16.81 pg and 19.37 pg, respectively. Mitotic and meiotic chromosome counts from L. perigrinum and L, purpuratum showed that both parents and their hybrids had identical chromosome numbers (2n = 24), and that the species were closely related. Morphological analyses of leaves and flowers showed that the hybrids displayed a number of features intermediate between both parents.

Interspecific hybrids betweenLimonium perigrinum andL. purpuratum were obtained usingL. perigrinum as the female parent. No hybrids were produced by the reciprocal cross. Twelve- to 15-day-old embryos were rescued and cultured within their embryo sacs on modified B5 or KM medium. After two to three days the embryos were excised from their embryo sacs and re-plated on to fresh medium. When the embryo-derived plantlets had attained a length of 1 cm they were transferred to a modified MS medium containing BA and NAA for shoot proliferation. Plantlets were transferred to modified MS medium supplemented with IBA for 24 hours for root initiation then to a modified growth-regulator-free MS medium for root growth. After a further 28 days the plantlets were transferred to soil-less medium for acclimatisation. The hybrid characteristics of one of the 15 embryo-derived plants were determined by flow cytometry and by examination of morphological features. The mean DNA contents of 2C nuclei fromL. perigrinum, the hybrid andL. purpuratum were 13.98 pg, 16.81 pg and 19.37 pg, respectively. Mitotic and meiotic chromosome counts fromL. perigrinum andL. purpuratum showed that both parents and their hybrids had identical chromosome numbers (2n=24), and that the species were closely related. Morphological analyses of leaves and flowers showed that the hybrids displayed a number of features intermediate between both parents.

Ninety two adventitious shoots (somaclones) were regenerated from leaf-derived callus of Actinidia deliciosa var. deliciosa cv. Hayward. Each somaclone was multiplied in vitro through axillary bud culture to produce several individual clonal shoots. A total of 671 shoots were exflasked but only 223 (33%) resulted in rooted plants. These represented 46 of the original 92 somaclones. Shoot apices from representative plants of each of the 46 somaclones were analysed by flow cytometry to detect changes in their DNA ploidy. Two somaclones had twice the DNA ploidy of hexaploid Hayward (6C) indicating that they were DNA dodecaploids (12C). Seven clonal derivatives of these two somaclones were also DNA dodecaploid. The mean length of their stomatal guard cells was significantly greater than those from hexaploid somaclones. This is the first description of a method to produce DNA dodecaploid kiwifruit plants.

Nuclei were extracted from shoot apices of Actinidia species, treated with ribonuclease, stained with propidium iodide, and then analysed by flow cytometry. Nuclei from shoots and from callus of in vitro cultures were also analysed. Diploid. tetraploid, hexaploid species, and hybrids between diploid and hexaploid could be accurately identified. No mixoploidy or aneuploidy was found in shoots from potted plants or from shoots of tissue-cultured plants following repeated subculturing. However, two cytotypes (DNA dodecaploid) of A. deliciosa were identified in plant populations derived by adventitious organogenesis from callus. The cytotypes were stable over a 2 year period. The nuclear DNA content of Actinidia species was determined by co-chopping shoot apices with Hordeum, Vigna, and Zea standards. Nuclear DNA contents were 1.53, 3.09, and 4.43 pg DNA per 2 C nucleus for A. chinensis var. chinensis, A. arguta var. arguta, and A. deliciosa var. deliciosa, respectively.

Plants of lisianthus (Eustoma grandiflorum (Griesbach)Schinners=Lisianthus russellianus Hook.) were regenerated from protoplasts and grown in pots until flowering. Vegetative and floral characteristics were measured and compared with parent plants. Larger leaves and petals and longer guard cells, sepals and filaments were recorded from protoplast-derived plants suggestive of polyploidy. The nuclear DNA contents of protoplast-derived and parental plants were determined by flow cytometry. Protoplast-derived plants were confirmed as DNA tetraploid by flow cytometry with a DNA index of 1.95. Their nuclear DNA content was measured as 6.33±0.04 pg DNA per 2C nucleus compared with 3.26±0.10 pg DNA per 2C nucleus from parental plants. Polyploidisation induced during protoplast regeneration offers an alternative to that of colchicine treatment.

Vine growth, pruning requirements, yield, and postharvest storage of kiwifruit (Actinidia deliciosa) grown on five different vine support structures were compared over 5 years from grafting. Support structures were winged T-bars and Pergolas (standard structures), Lincoln T-bars, divided T-bars, and A-frames. Cumulative length of fruiting canes in the 3 years to full canopy closure was greatest for Lincoln T-bars, A-frames, and pergolas, and least for winged and divided T-bars. The proportion of budbreak was higher on pergolas than on the three T-bar systems and was least on A-frames. Floral budbreak and flowers per floral shoot were also lower on A-frames than on the other systems. Cumulative yields of export fruit were highest for pergolas and winged T-bars, and lowest for A-frames. Differences in postharvest storage were detected between fruit from different structures, but these differences were not consistent among years. The time required to prune each vine was least for pergolas and winged T-bars. Vines on A-frame structures took substantially more time to prune than vines on pergola structures.

Correlations between seed number and fruit weight, and between seed distribution and fruit shape were established for Chinese gooseberry (Actinidia chinensis Planch.) fruit. Ovaries containing few seeds develop into small fruit, and various growth regulators, either alone or in combination, were applied to fruitlets containing few seeds in an attempt to increase fruit size. In general, auxins (2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, β-naphthoxyacetie acid, indoleacetylaspartate), gibberellins (GA3, GA4–7), and cytokinins (6-benzylaminopurine, zeatin) when applied alone did not stimulate fruit development; nor did combinations of auxin + gibberellin, and gibberellin + cytokinin. However, auxin (2,4-D or 2,4,5-T) + 6-benzylaminopurine and auxin + cytokinin + gibberellin markedly stimulated fruit growth especially when treated fruit contained over 200 seeds. These results are discussed in terms of current theories on hormonal control of fruit growth.

The development of fruit and seed tissues in Chinese gooseberry (Actinidia chinensis Planch. cv. ‘Monty’) was examined at intervals after flowering. Cell division in all fruit tissues commenced immediately after flowering and persisted in the outer pericarp, inner pericarp, and central core for 23, 33 and 111 days, respectively. The fruit growth curve was double sigmoid owing to an initial period of cell enlargement in all tissues (Stage I, 0–58 day!) followed by a period of retarded enlargement (Stage II, 58–76 days) and a further period of enlargement in the inner pericarp (Stage III, 76–160 days after flowering). The structure of the seed was unusual in that the nucellus possessed a well defined hypostase, and the endosperm and embryo were surrounded by an endothelium. Only one, uniseriate, integument was present which subsequently developed into a thickened tests. The cellular nucellus and endosperm developed concomitantly until the end of Stage II and were absorbed, in part, during Stages II and III by the developing embryo.