Asparagus ( Asparagus officinalis L.) is a well-managed/assisted crop, with good water and nutrient availability ( Yeasmin et al., 2013 ). Asparagus decline is associated with both abiotic and biotic factors. Abiotic factors associated with the
Rumana Yeasmin, Stephen P. Bonser, Satoru Motoki, and Eiji Nishihara
Thomas S. Brettin and Ken C. Sink
We have used isozyme techniques (SGE) to assess variation and begin construction of a genetic map of the Asparagus officinalis genome. Isozyme extraction buffers, electrophoretic buffer systems, and isozyme stability during storage were evaluated. Isozyme expression under different environmental conditions was also examined. Thirty-four enzymes were evaluated for their usefulness as genetic markers in A. officinalis. Of these 34, 13 had sufficient activity and resolution on the gels for isozyme analysis. Of the 13 enzyme systems resolved, polymorphisms were observed in aconitase, endopeptidase, malate dehydrogenase, phosphoglucomutase, and shikimate dehydrogenase. Segregation of putative alleles is presented for ACON, END, MDH, PGM and SKDH isozymes. Co-segregation data showed linkage between a SKDH locus and a PGM locus. The isozyme analysis also included Asparagus densiflorus `Sprengeri' and revealed that aspartate aminotransaminase, endopeptidase, and triosephosphate isomerase would be potentially useful for verification of cell fusion products between the two species.
Rajeev Arora, Michael E. Wisniewski, and Donald J. Makus
Frost damage to `Jersey Giant' asparagus (Asparagus officinalis L.) spears was evaluated in noncovered and black plastic-covered field plots following a spring frost episode. In the noncovered plots, 78% of spears were killed as compared to only 17% under the plastic rowcovers. Laboratory studies using natural frost simulations indicated that the spears of both treatments were frost hardy to -2.8C. Air temperature data in the field plots during the frost episode indicated that spears in noncovered plots were at lower temperatures (-4.0 to -4.8C vs. -2.8C) ≈4 to 5 hours longer than spears under rowcovers. The large difference in the spear-kill may be due to the difference in the combined effect of the degree and duration of freezing to which the spears had been exposed.
R. Biffi, F.M. Restivo, F. Tassi, E. Caporali, A. Carboni, G.P. Marziani, A. Spada, and A. Falavigna
The use of a sex-linked molecular marker for early sex diagnosis in the dioecious species Asparagus officinalis L. was evaluated. Screening of random genomic probes as a part of a restriction fragment length polymorphism mapping project resulted in the identification of a sex-linked (6.9 cM) marker. The usefulness of this molecular tool was compared to morphological markers for prediction of gender in several genotypes. The level of polymorphism detected by this probe was high, and the level of incorrect sex attribution, as determined by this method, was low (≈7%).
Takahiro Sonoda, Atsuko Uragami, and Kazuhiko Kaji
Asparagus officinalis L. cultivars were evaluated for resistance to asparagus stem blight caused by Phomopsis asparagi (Sacc.) Bubák under controlled environmental conditions. The plants were inoculated with the vinyl tube and cotton inoculation method. Disease severity assessments, based on the percentage of diseased plants and the disease index, were made 4 weeks after inoculation. Estimates of the percentage of diseased plants ranged from 33% to 80%, and the disease index ranged from 28 to 79. None of the cultivars and lines showed high resistance, but there were significant differences in disease susceptibility among the cultivars and lines.
Sandip Mukhopadhyay and Yves Desjardins
The effects of culture media, culture modes, and carbon sources on plating efficiencies of protoplasts of two genotypes of Asparagus officinalis L. were investigated. Protoplasts grew best in a semisolid culture system containing half-strength MS medium with 1 mg NAA/liter, 0.5 mg zeatin/liter, 0.6 M glucose, and 0.1% Gelrite. The plating efficiencies were 12.5% and 8.1% for genotypes G 203 and G 171, respectively. Embryogenic calli were produced from protoplast-derived microcalli after culturing on MS medium with 1 mg 2,4-D, 3% sucrose, and 0.2% Gelrite. The somatic embryos were initiated, matured, and then germinated to plantlets in MS medium containing 0.1 mg NAA/liter, 0.3 mg 2-iP/liter (EMM), and different levels of carbohydrates. Transfer of somatic embryos from EMM with 10% glucose to EMM containing 2% sucrose produced the highest number of bipolar embryos and plantlets. The plantlets regenerated shoots and roots in MS medium with 3% sucrose, 0.1 mg NAA/liter, 0.1 mg kinetin/liter, and 1.28 mg ancymidol/liter. Cytological analysis of these plants revealed 2n = 20 chromosomes.
Satoru Motoki, Tianli Tang, Takumi Taguchi, Ayaka Kato, Hiromi Ikeura, and Tomoo Maeda
Asparagus ( Asparagus officinalis L.) is a perennial plant belonging to the Asparagaceae family and is a popular vegetable consumed in many different areas of the world ( Benson, 2012 ). It can be easily divided into edible and inedible parts. It
Ling Li, Takashi Watanabe, Atsuko Uragami, Hiroaki Kitazawa, and Xiangyou Wang
Asparagus ( Asparagus officinalis L.) is a popular stem vegetable consumed worldwide. It is a source of functional substances including rutin and protodioscin ( Wang et al., 2003 ). A recent statistical report suggested that China is the largest
Satoru Motoki, Takumi Taguchi, Ayaka Kato, Katsuhiro Inoue, and Eiji Nishihara
Asparagus ( Asparagus officinalis L.) is a perennial plant belonging to the Asparagaceae family and a popular vegetable cultivated and consumed in many different areas of the world ( Benson, 2012 ). Asparagus is rich in healthy functional
Sandip Mukhopadhyay and Yves Desjardins
Transient expression of electroporation-mediated DNA uptake was monitored in callus-derived protoplasts of two asparagus (Asparagus offcinalis L.) genotypes by measuring the GUS activity. The level of expression and the viability of the protoplasts were influenced by the voltage and duration of the electric pulse. An increased plasmid DNA concentration and the presence of polyethylene glycol (PEG) in the electroporation medium enhanced the transient expression level. A considerable increase in GUS activity was observed in the presence of both PEG and heat-shock treatments than with PEG treatment alone. An optimal level of GUS activity was obtained after electroporation with a capacitive discharge of 500 V/cm and 94 ms duration. The two genotypes differed in their responses in vitro and also showed variable levels of transient expression. The present technique was suitable to obtain transgenic plants, as histochemical GUS assay revealed GUS activity in the protoplast-derived microcolonies as well as in callus tissues.