Phytophthora capsici Leonian, the causal agent of crown rot, foliar blight, and fruit rot in many vegetable crops ( Hausbeck and Lamour, 2004 ). Currently, there are no commercial C. pepo cultivars immune to P. capsici , but sources of resistance to
unproductive. Wood et al. (2004a , 2004b ) conclusively demonstrated that mouse-ear was caused by nickel deficiency. Routine foliar application of a commercially available nickel product eliminated this problem. Crown gall has the broadest host range of any
produce fruit in the first 2 years was shown to reduce crown and root growth and fruit production in Year 3 relative to uncropped plants ( Strik and Buller, 2005 ). However, growers experience an increased rate of return when vigorous plants are pruned to
. lundelliana Bailey and C. okeechobeensis ssp. okeechobeensis Bailey, have been recently studied as useful sources for disease resistance such as powdery mildew and P. capsici crown rot resistance ( Cohen et al., 2003 ; Contin and Munger, 1977
The stramenopile plant pathogen Phytophthora capsici Leon. causes root, crown, and fruit rot on a large number of high-value vegetable crops ( Granke et al., 2012 ; Hausbeck and Lamour, 2004 ). Initially described by Leonian as a pathogen of
, and have frequently produced nonrepeatable results ( Huang et al., 1990 ; Williams et al., 1966 , 1967 ). Detached leaf assays have been used to maintain cultures of the crown rust fungus ( P. coronata ) from oats ( Avena sativa L.); however, it
In recent years, new gentian cultivars (particularly Gentiana triflora Pall and Gentiana scabra Bunge) have been released for production of cut flowers or potted plants. As a herbaceous perennial, gentians overwinter as a crown comprised of an
also an important ornamental plant due to its graceful crown, straight trunk, and attractive leaves ( Jin et al. 2009 ). Additionally, the bark and leaves of Z. schneideriana are especially significant in Chinese traditional medicine ( Shao and Zhang
Abstract
Dormant rhubarb crowns do not force well until their rest period or physiodormancy (7) has been broken by sufficient chilling in the field during late fall. There are many reports that during exposure of dormant plants to cold, the free amino acids contents change. Asen and Stuart (1) found that dormant leaves and buds of Hydrangea macrophylla showed an increase of some free amino acids after 6 weeks of storage at 4 to 5°C. Another worker (8) reported that in one alfalfa variety there was a 20% increase of acids from August to December. Schneider (4) found that the levels of some free amino acids in leaves of Ilex crenata nigra rooted cuttings changed during storage at cool temperatures. In this study buds and roots of dormant rhubarb crowns were analyzed to determine the free amino acids present and also possible changes in acids levels that might indicate the end of the rest period.
Abstract
Ethylene (C2H4) was higher in the internal atmosphere of crown gall infected rose bushes than in healthy plants. C2H4 was higher in the crown and root tissues than in the top of normal as well as crown gall infected plants.