جستجوی مقالات مرتبط با کلیدواژه "خوگیری" در نشریات گروه "زیست شناسی"

In order to assess zebrafish swimming behaviour and colour preferences, 16 adult zebrafish were used individually using a T-maze model. Behavioural indices such as habituation time in the start box, approaching time to the decision area, the number of crossings and the time spent in each combination of coloured arms (green-red and blue-yellow) were calculated. Habituation time in the start box and approaching time to the decision area were 300 and 120 s, respectively. The results indicated that zebrafish have more crossings to the red arm and preferred red colour rather than green colour. (p < 0.05). But, there was no significant difference for the number of crossings in the blue-yellow combination (P>0.05). Also, the time spent in each combination of coloured arms was not significant (P>0.05). Based on the current results, zebrafish have the ability to discriminate between colours and the T-maze is a valid tool for assessing colour preferences in zebrafish.

Chilling stress is major limiting factor on growth and development of tropical crops like cucumber in early of growing season. In this research, the possibility of chilling hardening of cucumber seedlings was investigated through pretreatment of drought and temperature. The factorial experiment was consisted of two factors including cucumber cultivars (i.e. Super dominos and Super star) and hardening treatments (control, 10 °C, and 15 °C as well as 10% and 20% PEG) based on CRD in three replications in 2017. After applying treatments and providing them 48 h opportunity to be recovered, the seedlings were subjected to 3 °C for a six days period and 6 h for each day. The results showed that hardening increased cucumber growth under chilling stress. Hardening treatments improved seedlings’ chlorophyll content, chlorophyll a/b ratio, relative water content, proline accumulation, and hydrogen peroxide while reducing electrolyte leakage content. It was not observed a significant difference between cultivars in terms of measured traits. The highest chilling tolerance was obtained by 10 and 20% PEG. Overall, the results of this experiment showed that employing drought and temperature pretreatments are able to mitigate the harmful effects of chilling on cucumber seedlings.