fa ارزیابی مقاومت به سرمای رشد ساقه‌چه در برخی از ارقام برنج در مرحله جوانه‌زنی پژوهشي Research <p> <strong> در </strong><strong>تحقیق </strong><strong>حاضر </strong><strong>تأثیر سرما روی رشد ساقه‌چه‌ در 18 </strong><strong>ژنوتیپ </strong><strong></strong><strong>برنج در قالب دو آزمایش جداگانه مورد بررسی قرار </strong><strong>گرفت. </strong><strong>آزمایش اول </strong><strong>به صورت فاکتوریل در قالب طرح پایه بلوک‌های کامل تصادفی در سه تکرار اجرا شد. در این آزمایش، دو فاکتور شامل ژنوتیپ در 18 سطح و درجه حرارت </strong><strong>در پنج<a name="OLE_LINK64"></a><a name="OLE_LINK63"> سطح دمایی ( </a>9، </strong><a name="OLE_LINK55"></a><a name="OLE_LINK54"><strong>13، 17، 21 و<br></strong></a><strong>C </strong><strong>° </strong><strong>25 </strong><strong>) بود. در </strong><a name="OLE_LINK61"><strong>دمای </strong></a><strong></strong><strong>C </strong><strong>° </strong><strong>9 </strong><strong>، بذور ژنوتیپ‌ها جوانه‌ نزدند. پس از پایان اعمال هر تیمار دمایی، طول ساقه‌چه در گیاهچه‌ها اندازه‌گیری شد. نتایج تجزیه واریانس نشان داد که اثر </strong><strong>دما </strong><strong>، <a name="OLE_LINK109"></a><a name="OLE_LINK106">ژنوتیپ </a>و اثرمتقابل دو فاکتور بر طول ساقه‌چه در سطح احتمال 1 درصد معنی‌دار بود. اعمال تنش سرما موجب کاهش طول ساقه‌چه در ارقام مورد مطالعه شد. دو رقم تایچونگ و صدری بیشترین میزان طول ساقه‌چه را در سه درجه حرارت </strong><strong>13، 17 و </strong><strong>C </strong><strong>° </strong><strong></strong><strong>21 نشان دادند. درصد <a name="OLE_LINK159"></a><a name="OLE_LINK66"></a><a name="OLE_LINK65">کاهش طول ساقه‌چه </a>از مقایسه <a name="OLE_LINK90"></a><a name="OLE_LINK74">طول ساقه‌چه تحت تأثیر دو تیمار دمایی </a></strong><a name="OLE_LINK69"></a><a name="OLE_LINK68"><strong>13 و </strong></a><strong>C° </strong><strong>25 </strong><strong>محاسبه شد. میزان </strong><strong>کاهش طول ساقه‌چه در ارقام هاشمی، گرده و نعمت کمتر از 10 درصد بود که نشان می‌دهد این ارقام جزء ارقام مقاوم به سرما ‌بودند. </strong><strong>آزمایش دوم به صورت طرح پایه بلوک کامل تصادفی در سه تکرار انجام شد. در این آزمایش، بذور ابتدا به مدت 72 ساعت در <a name="OLE_LINK60">دمای</a> </strong><strong>C° </strong><strong>25 قرار داده ‌شدند و سپس به مدت <a name="OLE_LINK73"></a><a name="OLE_LINK72">96 ساعت </a><a name="OLE_LINK115"></a><a name="OLE_LINK112">دما روی </a></strong><strong>C° </strong><strong>10 </strong><strong>تنظیم شد. </strong><strong><a name="OLE_LINK118"></a><a name="OLE_LINK117">دما مجدداً به </a></strong><a name="OLE_LINK103"></a><a name="OLE_LINK102"><strong>C° </strong></a><strong>25 </strong><strong>افزایش داده شد و به مدت 72 ساعت تیمار دمایی</strong><strong>C° </strong><strong>25 روی گیاهچه‌ها اعمال گردید. </strong><strong>طول ساقه‌چه‌ها در دو مرحله شامل پس از اعمال دمای </strong><strong>C° </strong><strong>10 به مدت 96 ساعت </strong><strong></strong><strong>(<a name="OLE_LINK184"></a><a name="OLE_LINK183"> طول 1 </a>) و اعمال دمای </strong><strong>C° </strong><strong>25 به مدت 72 ساعت </strong><strong></strong><strong>(طول 2) اندازه‌گیری شد. اختلاف <a name="OLE_LINK92"></a><a name="OLE_LINK91">طول ساقه‌چه در دو مرحله </a>محاسبه و تحت عنوان <a name="OLE_LINK200"></a><a name="OLE_LINK105"></a><a name="OLE_LINK104">رشد مجدد ساقه‌چه </a>نامیده شد. تجزیه واریانس نشان داد که اثر ژنوتیپ بر رشد مجدد ساقه‌چه معنی‌دار بود. بر اساس دو صفت <a name="OLE_LINK210"></a><a name="OLE_LINK209">کاهش طول ساقه‌چه و </a><a name="OLE_LINK100"></a><a name="OLE_LINK98">رشد مجدد ساقه‌چه </a>، رقم گرده به عنوان رقم خیلی مقاوم تشخیص داده شد. </strong><strong></strong></p> <span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">In this research the effects of cold were evaluated on <a name="OLE_LINK199"></a><a name="OLE_LINK198"></a><a name="OLE_LINK156"></a><a name="OLE_LINK155"></a><a name="OLE_LINK154"><span style="mso-bookmark: OLE_LINK155"><span style="mso-bookmark: OLE_LINK156"><span style="mso-bookmark: OLE_LINK198"><span style="mso-bookmark: OLE_LINK199"><font face="Times New Roman" size="3">coleoptile</font></span></span></span></span></a><font face="Times New Roman"><font size="3"><span style="mso-bookmark: OLE_LINK198"><span style="mso-bookmark: OLE_LINK199"> growth </span></span>of 18 rice genotypes in two separate experiments. The first </font></font><a name="OLE_LINK111"></a><a name="OLE_LINK110"><span style="mso-bookmark: OLE_LINK111"><font face="Times New Roman" size="3">experiment</font></span></a> </span><a name="OLE_LINK181"></a><a name="OLE_LINK176"><font size="3"><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"><span style="mso-bookmark: OLE_LINK181"><font face="Times New Roman">was carried out as factorial based on randomized complete block design</font></span></span><span style="mso-bookmark: OLE_LINK181"><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"> </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">with three replications</span></span></font></a><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">. In this experiment, two factors were including genotypes </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">at 18 levels and temperature at 5 levels (</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">9, 13, 17, 21 and 25 C°</span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">)</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">. The seeds of genotypes don’t germinate at 9 C°. <a name="OLE_LINK177">The </a><a name="OLE_LINK161"></a><a name="OLE_LINK160"><span style="mso-bookmark: OLE_LINK161"><span style="mso-bookmark: OLE_LINK177"><font face="Times New Roman" size="3">length of coleoptile </font></span></span></a></span><span style="mso-bookmark: OLE_LINK161"></span><span style="mso-bookmark: OLE_LINK160"></span><span style="mso-bookmark: OLE_LINK177"><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">was measured </span></span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">in plantlets at the end of using of each temperature factor.</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"> Analysis of variance revealed </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">that the effect of temperature, genotype and interaction effects of two factors were significant on </span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">length of coleoptile </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">at 1% probability levels.</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"> The low temperature treatments decreased the growth of coleoptile in all of the studied cultivars. Taichung and Sadri showed a significantly bigger coleoptile length at the three low temperature treatments including 13, 17, 21 and <a name="OLE_LINK158"></a><a name="OLE_LINK157"><span style="mso-bookmark: OLE_LINK158"><font face="Times New Roman" size="3">25 C</font></span></a>°. <a name="OLE_LINK169"></a><a name="OLE_LINK162"><span style="mso-bookmark: OLE_LINK169"><font face="Times New Roman" size="3">The percentage of coleoptile reduction </font></span></a>was calculated form comparison of the length of coleoptile at 13 and 25 C°. The coleoptile reduction rate was lower than 10 percentages in Hashemi, Gerde and Neamat, indicating these varieties as tolerant varieties to cold stress. Second experiment </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">was carried out on randomized complete block design</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"> </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">with three replications</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">. In <a name="OLE_LINK170"></a><a name="OLE_LINK146"><span style="mso-bookmark: OLE_LINK170"><font face="Times New Roman" size="3">this experiment</font></span></a>, the seeds were placed in 25 C° for 72 h and then the temperature was adjusted to 10 C° for 96 hr. Temperature was further increased to 25 C° and treated plantlets to this temperature for 72 h. The <a name="OLE_LINK190"></a><a name="OLE_LINK189"><span style="mso-bookmark: OLE_LINK190"><font face="Times New Roman" size="3">length</font></span></a> of coleoptile </span><span style="FONT-FAMILY: "TimesNewRoman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">was measured in two stage contain after </span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">10 C° for 96 hr <a name="OLE_LINK197"></a><a name="OLE_LINK196"><span style="mso-bookmark: OLE_LINK197"><font face="Times New Roman" size="3">(length 1)</font></span></a> and 25 C° for 72 hr (length 1). The difference between these two lengths were calculated and </span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">called </span><a name="OLE_LINK204"></a><a name="OLE_LINK201"><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA"><span style="mso-bookmark: OLE_LINK204"><font face="Times New Roman" size="3">coleoptile regrowth</font></span></span></a><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: SimSun mso-bidi-font-family: '2 Nazanin' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: AR-SA">. Analysis of variance indicated that the effect of genotype were significant on coleoptile regrowth. Gerde was as a tolerant variety due to percentage of reduction in coleoptile length and coleoptile regrowth. </span> برنج، درجه حرارت، مقاومت به سرما، طول ساقه‌چه Rice, Temprature, Cold tolerance, Coleoptile length 108 121 http://jcb.sanru.ac.ir/browse.php?a_code=A-10-2-9&slc_lang=fa&sid=1 پیمان شریفی 100319475328460054 100319475328460054 Yes