F. J. Novak

Bio: F. J. Novak is an academic researcher from International Atomic Energy Agency. The author has contributed to research in topics: Somatic embryogenesis & Callus. The author has an hindex of 11, co-authored 14 publications receiving 1361 citations.

Somatic embryogenesis from cultured leaf segments of Zea mays.

Abstract: Basal leaf segments of 3 to 4 week old maize (Zea mays L.) seedlings plated on SH medium with 30 μM dicamba produced embryogenic callus and/or somatic embryos. Histological evidence showed that some of the embryos arose directly from the explant. When leaf segments with embryos were transferred to MS medium with 1.0 μM NAA, 1.0 μM IAA, 2.0 μM 2iP, and 60 g/l sucrose, the embryos germinated and the resulting seedlings could be established in culture tubes. These responses were obtained from three inbred lines, CHI31, S615, and S7.

Flow cytometric estimation of nuclear DNA amount in diploid bananas (Musa acuminata andM. balbisiana)

Abstract: Cell nuclei were isolated from leaf tissues of wild banana (Musa balbisiana, M. acuminata ssp.banksii andM. acuminata ssp.errans) and of the two vegetative clones of diploid cultivar “Pisang Mas”. Relative fluorescence intensity was measured on propidium iodide-stained nuclei by flow cytometry. Nuclei isolated fromGlycine max with known nuclear genome size were used as internal standard to determine nuclear DNA content ofMusa in absolute units. The results of the study showed that the size of nuclear genome ofMusa is smaller than previously estimated. In general, it is smaller in comparison with many other angiosperms. Furthermore, it was found that nuclear DNA content ofM. balbisiana (genome BB) is significantly lower than that ofM. acuminata subspecies and cultivars (genome AA). This finding should permit estimation of genome composition in triploidMusa clones with expected hybrid composition. Flow cytometry is proposed as a useful technique with potential applications in taxonomy, breeding and biotechnology ofMusa.

Somatic Embryogenesis and Plant Regeneration in Suspension Cultures of Dessert (AA and AAA) and Cooking (ABB) Bananas ( Musa spp.)

Abstract: Proembryogenic calli were initiated from basal leaf sheaths and rhizome tissue on modified Schenk and Hildebrandt (SH) medium with 30 μM 3,6–dichloro–2–meth–oxybenzoic acid (Dicamba). Cell suspensions were maintained in half–strength Murashige and Skoog (MS) medium supplemented with 20 μM Dicamba. The development of somatic embryos was promoted in cell suspensions 3–4 weeks after subculture in liquid modified MS medium with 5 μM zeatin. Characteristic stages of embryonic development were recapitulated and histological examination confirmed bipolar organization of somatic embryos. Conversion into plantlets took place in double layer media system composed of solid half strength MS medium with 5 μM zeatin and 1 g/l charcoal and liquid, hormone–free, half strength MS medium. In four Musa genotypes several hundred plantlets were regenerated and transferred into soil where they continued to grow. Somatic embryogenesis represents a significant step in developing a new breeding strategy for apomictic banana and plantain species.

Mutation induction by gamma irradiation of in vitro cultured shoot-tips of banana and plantain (Musa cvs)

Abstract: Vegetative shoot apices composed of a meristematic dome with two pairs of leaf primordia were excised from in vitro-cultured shoots of seven clones of dessert banana (AA, AAA and AAAA), plantain (AAB) and bluggoe cooking banana (ABB). The mutation induction experiments were carried out with 60Co gamma irradiation of 15, 30, 45 and 60 Gy at a dose rate of 8 Gy min-1. Radiosensitivity was assessed by determining the relative increase of fresh weight of cultures and by the rates of shoot differentiation. Musa clones exhibited differences in radiosensitivity and post-radiation recovery. These differences were dependent on ploidy level and hybrid constitutions by genomes A (acuminata) and B (balbisiana). Considerable phenotypic variation was observed among plants regenerated from in vitro shoot-tips after mutagenic treatment. An early-flowering putative mutant plant of Grand Nain (GN-60 Gy/A) was selected in the glasshouse in the M1V4 generation. The mutant plant was micropropagated and its vegetative progeny was planted for field testing in a tropical environment. Leaf protein electrophoresis provided evidence of an altered genetic nature of the mutant plant in comparison with the original clone. The mutant GN-60 Gy/A showed a less densely staining protein of about 33 kDa Mwt and lacked three other proteins. In addition, two bands of esterase isozymes, characteristic for the original Grand Nain, were not detected in extracts of GN-60 Gy/A. The potential of induced mutagenesis for genetic improvement of banana and plantain is discussed and a scheme of in vitro mutation breeding is outlined.

Nuclear DNA content and in vitro induced somatic polyploidization cassava (Manihot esculenta Crantz) breeding

Abstract: The diploid (2C) amount of DNA in cassava (Manihot esculenta Crantz) is 1.67 picograms (pg) per cell nucleus. This value corresponds to 772 mega-base pairs in the haploid genome. The size of the nuclear genome in cassava is very small in comparison with other Angiosperms. Flow cytometry techniques were used to screen ploidy levels in a large population of in vitro plantlets treated with colchicine and oryzalin (3,5-dinitro-N4,N-dipropylsulphate). Culture of axillary node cuttings for 48 hours in liquid medium supplemented with 2.5 to 5.0 mM colchicine in combination with 2% dimethyl sulfoxide (DMSO) resulted in a high frequency (23 to 42%) of non-chimeric tetraploids in the V3 generation. Although mixoploidy may persist in as many as four cycles of vegetative propagation of node cuttings, solid (non-chimeric) tetraploids can be identified by flow cytometry among in vitro plantlets and then rapidly propagated for field testing. A somatic polyploidization system is proposed for implementation in cassava breeding programmes.

Inbred corn plant 89AHD12 and seeds thereof

Abstract: According to the invention, there is provided an inbred corn plant designated 89AHD12. This invention thus relates to the plants, seeds and tissue cultures of the inbred corn plant 89AHD12, and to methods for producing a corn plant produced by crossing the inbred corn plant 89AHD12 with itself or with another corn plant, such as another inbred. This invention further relates to corn seeds and plants produced by crossing the inbred plant 89AHD12 with another corn plant, such as another inbred, and to crosses with related species. This invention further relates to the inbred and hybrid genetic complements of the inbred corn plant 89AHD12, and also to the SSR and genetic isozyme typing profiles of inbred corn plant 89AHD12.

Inbred corn line LH283BtMON810

Abstract: An inbred corn line, designated LH283BtMON810, is disclosed. The invention relates to the seeds of inbred corn line LH283BtMON810, to the plants of inbred corn line LH283BtMON810 and to methods for producing a corn plant, either inbred or hybrid, by crossing the inbred line LH283BtMON810 with itself or another corn line. The invention further relates to methods for producing a corn plant containing in its genetic material one or more transgenes and to the transgenic plants produced by that method and to methods for producing other inbred corn lines derived from the inbred LH283BtMON810.

Inbred corn line PHHB9

Abstract: According to the invention, there is provided an inbred corn line, designated PHHB9. This invention thus relates to the plants and seeds of inbred corn line PHHB9 and to methods for producing a corn plant produced by crossing the inbred line PHHB9 with itself or with another corn plant. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line PHHB9 with another corn line or plant.

Inbred maize line PH0HC

Abstract: An inbred maize line, designated PH0HC, the plants and seeds of inbred maize line PH0HC, methods for producing a maize plant produced by crossing the inbred line PH0HC with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH0HC with another maize line or plant.

Estimation of nuclear DNA content in plants using flow cytometry.

Abstract: Flow cytometry (FCM) using DNA-selective fluorochromes is now the prevailing method for the measurement of nuclear DNA content in plants. Ease of sample preparation and high sample throughput make it generally better suited than other methods such as Feulgen densitometry to estimate genome size, level of generative polyploidy, nuclear replication state and endopolyploidy (polysomaty). Here we present four protocols for sample preparation (suspensions of intact cell nuclei) and describe the analysis of nuclear DNA amounts using FCM. We consider the chemicals and equipment necessary, the measurement process, data analysis, and describe the most frequent problems encountered with plant material such as the interference of secondary metabolites. The purpose and requirement of internal and external standardization are discussed. The importance of using a correct terminology for DNA amounts and genome size is underlined, and its basic principles are explained.