نشریه تحقیقات نوین در گیاه پزشکی
سال نهم شماره 4 (پیاپی 25، زمستان 1397)

In order to study seed germination responses of three species of Lolium to temperature regimes, salinity and drought stresses three separate experiment were conducted as a factorial based on completely randomized design at laboratory of ecology of Faculty of Agriculture, Science and Research Branch, Islamic Azad University in 2015. In frist experiment, factors were included three species of Lolium (poison ryegrass, Persian darnel and rigid ryegrass) and temperature at 12 levels (0, 3, 5, 7, 10, 12, 15, 20, 25, 30, 35, 40 0C). In second and third experiments effects of seven levels of salinity (0, 10, 20, 40, 80, 160 and 320 mmol) and seven levels of drought stress (0, -0.1, -0.2, -0.4, -0.6, -0,8 and -1 MPa) on germination percentage of three Lolium species were examined. Based on linear regression between germination rate and temperature, the cardinal temperatures: minimum (Tmin), maximum (Tmax) and optimum (To) were determined 2, 37 and 20ºC, for poison ryegrass, 0, 38 and 20 ºC for Persian darnel and 0, 38 and 23 ºC for rigid ryegrass, respectively. Three-parameter logestic model is well justified the relationship between different salinity and drought levels and germination percentage. Based on model, reduction of 50% of germination percentage in Persian darnel caused at intensified osmotic potential in comparison of two other species, so this species had more tolerance to salinity and drought stresses.

The objective of this study was to identify rice lines (genotypes) resistant to striped stem borer and to determine plant characteristics associated with resistance. In this research, a total of 63 rice lines were evaluated in the field under natural infestation conditions during 2016- 2017. The lines exhibited considerable variation for plant height (84.30-149 cm), stem diameter (3.7-6.3 mm), panicle length (21.1-32.9 cm), number of larvae (3.83-69.50), growth period (108-138 days), white heads infestation (1.11-11.72 %) and grain yield (3.7-8.2t.ha-1)in relation to the mentioned pest. The results showed that the white heads infestation percent had significantly correlated with plant height stem diameter and panicle length. And also, there was a significantly correlated the decrease of grain yield by increasing the stem diameter, more infestation and white heads. The cluster analysis based on the studied morphological characteristics showed that all genotypes were classified into three groups. So that, 8, 26 and 29 genotypes was located in A, B and C classes, respectively. Among all the genotypes, the lines of the third group (Class C) can be used as a source for breeding programs to achieve the new rice cultivars which is to be tolerant to rice striped stem borer pest.

Most of new acaricides evaluation were demanded against apple mite pest’s orchards in Iran. Effects of flufenzin 200 SC doses (0.2 and 0.3ml/lit) against Panonychus ulmi and Tetranychus urticae in apple orchards of Ardebil, West Azerbaijan, Khorasan Razavi and in Esfahan provinces were investigated during 2014 respectively. Other registered acaricides such as Spirodiclofen 240 SC, bifenazate 24% SC, fenpropathrin 10% EC, fenproximate 5% SC along with1.5% liquid detergent soap, water sprayed in control treatment were used in this study. Random apple leaves sampling at weekly interval followed from middle month of May and by observing mean 5 active mite stages on 30% of the collected leaves, treatments carried out at early morning hours. Efficiency of each treat done by random 40 leaves from middle part of apple trees collected at interval of one day before and 3,7,14, 21 days after treatment respectively. Mean mortality% analysis done by SAS software and ranked them according Duncan method. The higher P. ulmi mortality% by 0.2 ml/l of flufenzin dose treat recorded 92.45% and 95.82% at 3rd and 7th days after in Ardebil and reduced to 55.79% at 21st day respectively. Maximum P. ulmi mortality% caused by 0.3 ml/l of flufenzin dose recorded 86.47% and 81.79% at 14th and 21th days after in Mashhad area and on T. urticae observed between 66.07% to 72.17% during 3rd to 21st days after treatment in Esfahan. Highest mite pest control among registered acaricidal received for spirodiclofen acaricide and effects of all of them in comparison to earliest record found in reduction. Results indicated that by 480 g a.i. of flufenzin spraying in hectare under low mite pest incidence effective control in apple orchard expected.

Several species of Fusarium infect durum wheat plants in the eastern part of Algeria. Endophytic fungus from random wheat seeds were sampled from fifty locations in eastern Algeria and shows the existence of Fusarium chlamydosporum regarding the macroscopic and microscopic characteristics. Molecular identification using EF1 and ITS1 primers were confirmed the presence of Fusarium chlamydosporum for the first time on durum wheat seeds in Algeria. The pathogenicity test was carried out on three durum wheat varieties for determining the effect of this isolate on the coleoptile and basal part of durum wheat. The results show that F.chlamydosporum had a negative impact on seed germination of the three varieties tested. Indeed, the reduction in germination varies between 85 and 92% reduction on GTAdur and Waha varieties, respectively. More, F.chlamydosporum caused a reduction in coleoptiles length in all varieties ranging from 60.97 to 70.05% in GTAdur and Waha, respectively. On the other hand, it showed a very different impact on plant growth parameters. Thus, the action was much more pronounced on reducing the root system length and the fresh weight of the vegetative system of Waha variety equal to 75.04 and 71.15%, respectively, and it is notable for the fresh weight of the root system of Bousselam variety. These very high levels of infectivity prompt us to reconsider our vision for this species of Fusarium in treatment and certification programs.