Standardized Genetic Transformation Protocol for Chrysanthemum cv. ‘Jinba’ with TERMINAL FLOWER 1 Homolog CmTFL1a

Chrysanthemum (Chrysanthemum x morifolium Ramat.) cultivar Jinba is a distinctive short-day chrysanthemum that can be exploited as a model organism for studying the molecular mechanism of flowering. The commercial value of Jinba can be increased in global flower markets by developing its proper regeneration and genetic transformation system. By addressing typical problems associated with Agrobacterium-mediated transformation in chrysanthemum, that is, low transformation efficiency and high cultivar specificity, we designed an efficient, stable transformation system. Here, we identify the features that significantly affect the genetic transformation of Jinba and standardize its transformation protocol by using CmTFL1a as a transgene. The appropriate concentrations of various antibiotics (kanamycin, meropenem and carbenicillin) and growth regulators (6-BA, 2,4-D and NAA) for the genetic transformation were determined to check their effects on in vitro plant regeneration from leaf segments of Jinba; thus, the transformation protocol was standardized through Agrobacterium tumefaciens (EHA105). In addition, the presence of the transgene and its stable expression in CmTFL1a transgenic plants were confirmed by polymerase chain reaction (PCR) analysis. The CmTFL1a transgene constitutively expressed in the transgenic plants was highly expressed in shoot apices as compared to stem and leaves. Overexpression of CmTFL1a led to a delay in transition to the reproductive phase and significantly affected plant morphology. This study will help to understand the biological phenomenon of TFL1 homolog in chrysanthemum. Moreover, our findings can explore innovative possibilities for genetic engineering and breeding of other chrysanthemum cultivars.

Chrysanthemum stem necrosis virus. [Distribution map].

A new distribution map is provided for Chrysanthemum stem necrosis virus Virus: Bunyaviridae: Tospovirus (tentative species) Hosts: Chrysanthemum X morifolium and tomato (Lycopersicon esculentum). Information is given on the geographical distribution in EUROPE, Netherlands, Slovenia, UK, SOUTH AMERICA, Brazil, Minas Gerais, Sao Paulo.

Aphelenchoides ritzemabosi. [Distribution map].

A new distribution map is provided for Aphelenchoides ritzemabosi (Schwartz) Steiner & Buhrer Nematoda: Aphelenchida: Aphelenchoididae Hosts: Mainly Chrysanthemum x morifolium, also strawberry (Fragaria x ananassa[Fragaria ananassa]), Dahlia and other plants. Information is given on the geographical distribution in EUROPE, Bulgaria, Denmark, Germany, Hungary, Ireland, Italy, Mainland Italy, Latvia, Netherlands, Poland, Portugal, Madeira, Russia, Southern Russia, Western Siberia, Spain, Canary Islands, Mainland Spain, Switzerland, UK, Ukraine, Yugoslavia (Fed. Rep.), ASIA, China, Guizhou, India, Himachal Pradesh, Jammu and Kashmir, Japan, Honshu, Kazakhstan, Korea Republic, Uzbekistan, AFRICA, Mauritius, South Africa, NORTH AMERICA, Mexico, USA, California, Colorado, Florida, Wyoming, SOUTH AMERICA, Brazil, Bahia, Sao Paulo, Chile, Venezuela, OCEANIA, Fiji, New Zealand.

Growth of Hardy Chrysanthemums in Containers of Media Amended with Composted Municipal Sewage Sludge

Four hardy Chrysanthemum X morifolium (Ramat) (chrysanthemum) cultivars were grown in peat sand media amended with 2 sources of sewage sludge compost at 50, 60 and 67% of the media by volume. Chrysanthemums growing in the 50% to 60% by volume composted sewage sludge treatments and top dressed with complete or only N slow-release fertilizers were comparable to plants growing in a commercially available potting medium with a complete fertilizer. Media containing 50 and 60% compost with a pH range of 6.2 to 6.9 supplied trace elements and most of the P and K necessary for normal plant growth. The use of a surfactant increased the fresh weight in some compost blends.