ABSTRACT Genetic analysis for resistance to bacterial blight (Xanthomonas oryzae pv. oryzae) of 21 rice (Oryza sativa L.) cultivars was carried out. These cultivars were divided into two groups based on their reactions to Philippine races of bacterial blight. Cultivars of group 1 were resistant to race 1 and those of group 2 were susceptible to race 1 but resistant to race 2. All the cultivars ...

Soybean is one of the most important crops in Brazil and continuously generates demands for production technologies, such as cultivars resistant to diseases. In recent years, the Asian rust fungus (Phakopsora pachyrhizi Syd. & P. Syd 1914) has caused severe yield losses and the development of resistant cultivars is the best means of control. Understanding the genetic control and estimating para...

drought stress is a major factor limiting crop production. investigation of physiological characteristics related to drought tolerance and crop production may be useful in selecting drought tolerant cultivars as well as in improving crop yield. two drought tolerant (azar2 & back cross roshan) and two drought susceptible (marvdast & shiraz) cultivars were investigated in both greenhouse and fiel...

twenty-two bread wheat cultivars along with susceptible (sholeh) and resistant (azadi) control cultivars were evaluated for resistance to russian wheat aphid of two growth stages including seedling and stem elongation in greenhouse. five adult aphids per plant were used for infestation. leaf chlorosis at seedling and stem elongation stages and leaf rolling at seedling stage were measured. other...

This investigation was carried out with the aim of determining the effect of polyethylene glycol 6000 (PEG; 0, 3%, 6% and 9% w/v) treatment on six cultivars of Medicago sativa. PEG treatment significantly decreased the germination index in cultivars of Isfahani, Hamedani, Bami, Baghdadi, Yazdi and Ghare-Medicago, with the highest reduction in Ghare-Medicago and Hamedani cultivars by about 50% a...

The evaluation of biochemical markers is important for the understanding of the mechanisms of tolerance to salinity of Phaseolus beans. We have evaluated several growth parameters in young plants of three Phaseolus vulgaris cultivars subjected to four salinity levels (0, 50, 100, and 150 mM NaCl); one cultivar of P. coccineus, a closely related species reported as more salt tolerant than common...

In this study, the effect of 20 barley cultivars were evaluated on the life table parameters and digestive enzymatic activity of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) under laboratory conditions (28 ± 1°C, 60 ± 5% RH, and a photoperiod of 16:8 (L:D) h). Among barley cultivars tested developmental time of R. dominica immature stages was longest on cultivar ...

Selected cotton cultivars were evaluated for resistance to the southern root-knot nematode, Meloidogyne incognita, in greenhouse and field experiments. Cotton cultivars LA 887, Auburn 634, and NemX cotton were highly resistant to three North Carolina populations of root-knot nematode in greenhouse experiments compared to susceptible cultivars. The relative susceptibility of cultivars tested in ...

The effect of night temperature on the ̄owering of heat-tolerant and heat-sensitive cultivars of potted chrysanthemum (Chrysanthemum xgrandi ̄orum) was examined in four experiments over a period of 4 years. Temperature reductions were imposed only while the plants were under black cloth using a combination of air-conditioning and under-cloth ventilation. The two heat-sensitive cultivars tested w...

The legume Glycine max (soybean) plays an important economic role in the international commodities market, with a world production of almost 260 million tons for the 2009/2010 harvest. The increase in drought events in the last decade has caused production losses in recent harvests. This fact compels us to understand the drought tolerance mechanisms in soybean, taking into account its variabili...