Acacia koa seedlings were evaluated from plantings and commercial nurseries for colonization by Fusarium spp., particularly F. oxysporum, the putative cause of koa wilt/dieback disease in Hawaii. We sampled 162 seedlings, 90% of which were from nurseries on the islands of Hawaii, Maui, Kauai, and Oahu. Fusarium oxysporum was detected on about 78% of sampled seedlings. It was most prevalent on r...

The glyoxylate cycle is a modified form of the tricarboxylic acid cycle that converts C2 compounds into C4 dicarboxylic acids at plant developmental stages. By studying submerged rice seedlings, we revealed the activation of the glyoxylate cycle by identifying the increased transcripts of mRNAs of the genes of isocitrate lyase (ICL) and malate synthase (MS), two characteristic enzymes of the gl...

This paper examines the first year results from a silvicultural study of American, hybrid (BC2F3) and Chinese chestnut seedlings (Castanea spp. Mill.) on the Daniel Boone National Forest in southeastern Kentucky. After one year, no significant differences in growth were found among the silvicultural treatments. Hybrids and Chinese seedlings added significantly more height growth than the Americ...

Container-grown black spruce (Picea mariana (Mill.) B.S.P.) seedlings were planted in trays containing a sand and peat mixture, and placed in a climate-controlled greenhouse. One group of seedlings was kept well-watered, and another group was subjected to three cycles of drought. Gas exchange analysis showed that mesophyll photosynthetic function was largely unimpaired by drought. In contrast, ...

ABSTRACT A series of laboratory tests were conducted to investigate potential effects of fungus gnat (Bradysia impatiens) feeding damage on susceptibility of geranium seedlings (Pelargonium x hortorum) to infection by the root rot pathogen Pythium aphanidermatum. Effects were compared with those from similar tests in which the seedlings were mechanically wounded by severing the root tip with a ...

Root hairs, which arise from root epidermal cells, are tubular structures that increase the efficiency of water absorption and nutrient uptake. A low pH (pH 4) medium induced root hair formation in lettuce (Lactuca sativa L.) seedlings, and the decapitation of shoots inhibited root hair formation. The addition of shoot extract to the medium restored root hair formation in the decapitated lettuc...

Esteya vermicola (Ophiostomataceae) is an endoparasitic fungus that has great potential as a biological control agent against the pinewood nematode Bursaphelenchus xylophilus which causes pine wilt disease. We tested E. vermicola for control of pine wilt disease by spraying E. vermicola conidia on artificial wounds on pine seedlings, and the optimum E. vermicola treatment density and applicatio...

Cytochrome P450 monooxygenases play paramount roles in the detoxification of herbicides as well as in the synthesis of lignins, flavonoids, and phenolic acids. Biochemical analysis of triasulfuron metabolism in maize (Zea mays) seedlings has demonstrated that the P450(s) responsible for detoxification of this herbicide is induced by naphthalic anhydride (NA), a plant safener, and by triasulfuro...

Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of individual starch grains. Similarly, t...

Nursery grown seedlings of Pinus virginiana with infection by Pisolithus tinctorius (Pt) versus seedlings with naturally occurring mycorrhizae were used in greenhouse experiments to determine the influence of mycorrhizae on manganese and zinc uptake and distribution in seedlings. Unamended Pt mycorrhizal seedlings and those treated with 48.0 mg Mn/pot over a 2-week period accumulated significan...