We investigated the composition of free amino acids in walnut (Juglans regia L.) seeds (embryo and cotyledons). We also examined xylem transport of free amino acids in young seedlings grown in the absence of external nutrients. A relatively high concentration of free alanine was found in seed tissue, whereas a relatively high concentration of citrulline was detected in young seedlings. Citrulli...

Crown gall of walnut (Juglans sp.), caused by the bacterium Agrobacterium tumefaciens, greatly impacts the CA walnut industry. To determine the genetic diversity of A. tumefaciens throughout the Central Valley of CA, we collected isolates from ten walnut growing counties. A total of 340 A. tumefaciens biovar 1 isolates were collected and tested for the presence of the Ti plasmid by PCR; 190 iso...

To alleviate resource shortage, reduce the cost of materials consumption and the pollution of agricultural and forestry waste, walnut shell composites (WSPC) consisting of walnut shell as additive and copolyester hot melt adhesive (Co-PES) as binder was developed as the feedstock of selective laser sintering (SLS). WSPC parts with different ingredient proportions were fabricated by SLS and proc...

Several North American walnut species (Juglans spp.) are threatened by thousand cankers disease which is caused by the walnut twig beetle (Pityophthorus juglandis Blackman) and its associated fungal plant pathogen, Geosmithia morbida M. Kolarík, E. Freeland, C. Utley and N. Tisserat sp. nov. Spread of this disease may occur via movement of infested black walnut (Juglans nigra L.) wood. This stu...

Diabetes leads to reproductive dysfunctions by producing free radicals. It seems that using walnut can be effective in the damage induced by diabetes. The aim of the present study was to evaluate the effects of walnut consumption on sex hormones in diabetic Wistar male rats induced by STZ (streptozotocin). Diabetes animals were induced by STZ (60 mg/kg). Rats were randomly divided into 5 groups...

The enzyme polyphenol oxidase (PPO) catalyzes the oxidation of phenolic compounds into highly reactive quinones. Polymerization of PPO-derived quinones causes the postharvest browning of cut or bruised fruit, but the native physiological functions of PPOs in undamaged, intact plant cells are not well understood. Walnut (Juglans regia) produces a rich array of phenolic compounds and possesses a ...

Pistillate flower abortion (PFA) is the loss of nut-producing pistillate flowers early in the season, typically 2 to 3 weeks after bloom. PFA is the principal factor limiting productivity in ‘Serr’ walnut while affecting other cultivars to lesser and varying degrees. Research by Vito Polito at UC Davis showed that excessive pollen tubes growing down the style of the walnut pistillate flower pro...

Research this year in the laboratory and field continued to show that the bactericidal action of copper compounds could be greatly increased by amending them with iron. There are at least three different mechanisms which cause the increased efficacy: 1) When soluble iron is added to fixed coppers at amounts ranging from 10 to 100 ppm, the ferric iron interacts synergistically with the copper io...

Kazakhstan has very rich walnut genetic resources; however there is no ongoing walnut breeding program. Kazakhstan government has several projects in cooperation with Russia, USA, Bulgaria, Czech Republic and Poland for plant breeding purposes. In the present research walnut genetic resources originated from Jabağıl, Tulkıbas, Sayram, Lenger, and Botanical Garden of International Hodja Ahmet Ye...