Evaluation of resistance of selected cucumber lines to angular leaf spot (Pseudomonas syringae pv. lachrymans)

Angular leaf spot caused by bacteria Pseudomonas syringae pv. lachrymans is a very common cucumber disease, which causes serious yield losses. The objective of this study was to examine the selected cucumber lines regarding their resistance to this pathogen. Twelve cucumber lines bred at the Research Institute of Horticulture were evaluated and compared with the resistant inbred line GY 14 and the susceptible cv. ‘Wisconsin SMR 18’. Plants were inoculated under controlled conditions at cotyledon stage (experiment I) and at leaves stage (experiment II) with the highly aggressive strain of P. s. pv. lachrymans BO 1537. Dis-ease severity was scored 8 days after inoculation using a nine-point rating scale (9 – no symptoms or a few pin-point lesions; 1 – damage up to 100% of leaves). Distribution of plants across severity classes and low variation coefficient indi-cate that all evaluated cucumber lines showed rather good uniformity in their re-spective degrees of resistance to this pathogen. All the materials tested presented lower disease severity in cotyledons stage than in leaves stage. It was also noted that greater differentiation among the lines in regard to their resistance to the bacteria was observed in the leaves stage. Two lines PW 2 and PW 7 exhibited the highest resistance against P. s. pv. lachrymans and can serve as a useful source of this trait in future breeding efforts

Forwards the breeding of male sterile tomato lines with gene ms-10

The aim of the study conducted in 2012-2014 was to evaluate multi-breeding value of the tomato male-sterile lines (gene ms-10). Two (PWS 10, PWS 18) of the five tested lines showed the highest and most stable level of sterility. The good stability of sterility was also found in the two other ms-10 lines (PWS 12, PWS 21), which displayed a low number of fruits with seeds. In the case of the last tested line (PWS 19), regardless of the research year, partially fertile plants were observed. A large variation among tested lines was demonstrated in terms of most analysed agrobotanical traits, as well as the content of basic chemical components and health-enhancing constituents

Yeast cells can access distinct quiescent states

We conducted a phenotypic, transcriptional, metabolic, and genetic analysis of quiescence in yeast induced by starvation of prototrophic cells for one of three essential nutrients (glucose, nitrogen, or phosphate) and compared those results with those obtained with cells growing slowly due to nutrient limitation. These studies address two related questions: (1) Is quiescence a state distinct from any attained during mitotic growth, and (2) does the nature of quiescence differ depending on the means by which it is induced? We found that either limitation or starvation for any of the three nutrients elicits all of the physiological properties associated with quiescence, such as enhanced cell wall integrity and resistance to heat shock and oxidative stress. Moreover, the starvations result in a common transcriptional program, which is in large part a direct extrapolation of the changes that occur during slow growth. In contrast, the metabolic changes that occur upon starvation and the genetic requirements for surviving starvation differ significantly depending on the nutrient for which the cell is starved. The genes needed by cells to survive starvation do not overlap the genes that are induced upon starvation. We conclude that cells do not access a unique and discrete G0 state, but rather are programmed, when nutrients are scarce, to prepare for a range of possible future stressors. Moreover, these survival strategies are not unique to quiescence, but are engaged by the cell in proportion to nutrient scarcity