سیب (.( Malus x domestica Borkh رایجترین میوههای مناطق معتدله بوده و از زمانهای باستان در اروپا و آسیا کشت شده است .سیب از نظر اهمیت بعد از مرکبات، موز و انگور مقام چهارم را در بین میوهها داراست .کشور ایران بعد از چین، آمریکا و لهستان با تولید ۴/۲ میلیون تن سیب در سال، مقام چهارم را در جهان به خود اختصاص داده است .زیاد بودن دوره نونهالی در سیب، باعت طولانی تر شدن دوره اصلاحی گردیده و اصلاح این نبات را بسیار مشکل مینماید .دستکاری ژنتیکی زمان گلدهی، طول دورة نونهالی و عادت گلدهی سیب مستلزم شناخت ژنهای دخیل در فرآیند گلدهی و تکوین گل سیب و نیز بررسی نقش و عمل آنها میباشد .در این تحقیق، ژنتیک گلدهی سیب به روش) in silico روشصهای بیوانفورماتیکی (با استفاده از داده های EST سیب مورد بررسی قرار گرفته و ژنهای احتمالی سیب مشابه با ژنهای درگیر در گلدهی آرابیدوپسیس شناسایی گردیدند .همچنین، ژنهایbox - MADSسیب و آرابیدوپسیس با استفاده از نرم افزار های مختلف مورد بررسی و گروه بندی قرار گرفتند و ژنهای مختلفbox - MADSبه گروه های متفاوتی تخصیص داده شدند .برای ژنهای SOC۱/AGL۲۰ و TOE۱ سه ژن مشابه برای ژنهایGI ،PHYA ،PHYB ،EBS ،EMF۲ ،FWA ،ANT ،CRC ، AGL۲۴ دو ژن برای ژنهایCAL ،AP۲ ،RGA۱ ،VRN۱ ،FPA ،ADG۱ ،PGM ،SEX۱ ،UFO ،KNAT۲ ، NAP یک ژن برای دو ژن SMZ و SNZ فقط یک ژن برای ژنHST ، سهEST برای ژنCLF ، دو EST و در نهایت برای ژنهایSVP ، LD و MAF۲ یک EST معادل و مشابه در سیب شناسایی و مورد بحث و بررسی قرار گرفتند .در این راستا، برای همه ژنهای شناسایی شده درگیر در گلدهی سیب، میزان مشابهت آنها با ژنهای درگیر در گلدهی آرابیدوپسیس گزارش و همردیفی آنها نمایش داده شد .برای ژنهایWLC ،
Apples (Malus - domestica Borkh.) are the most prevalent fruit in temperate regions and have been cultivated from ancient times in Europe and Asia. Apples rank fourth in importance after citruses, bananas and grapes. Meanwhile, Iran after China, US and Poland is the forth apples producing (2.4 Mt) country. Prolonged juvenile period in apple elongates breeding cycles and makes the improvement of this crop a challenging process. Therefore, to find a way to shorten juvenility is the most important aim in apple breeding. To achieve the genetic manipulation of flowering time, juvenility and flowering habit of apple, it is necessary to identify the genes involved in apple flowering and floral development and to assess their function and role. In the present study, flowering genetics of apple has been elucidated through in silico analysis and the apple putative genes homologous to Arabidopsis flowering genes have been distinguished using apple EST data. Furthermore, apple and Arabidopsis MADS-box genes have been studied and classified using bioinformatic tools and software. There have been identified and discussed three homologous genes for each of SOC1/AGL20 and TOE1; two genes for each of GI, PHYA, PHYB, EBS, EMF2, FWA, ANT, CRC, AGL24; one gene for each of CAL, AP2, RGA1, VRN1, FPA, ADG1, PGM, SEX1, UFO, KNAT2, NAP; only one gene for both SMZ and SNZ; three EST's for HST; two EST's for CLF; and at last one EST for each of SVP, LD and MAF2. By the way, for all identified genes probably involved in apple flowering, the similarities with Arabidopsis genes were reported and alignments were illustrated. There was no homologous gene in apple for WLC, CLF, WUS, SPY, FLC, FCA, FVE, FD, FLD, FRI, LUC, HUA1 and HUA2. The probable reasons for this have been discussed. Amongst the studied genes MdMADS1, MdMADS3, MdSOC1a and MdSOC1b have been isolated and cloned. Consequently, it has been shown that MdMADS1 and MdMADS3 belong to AGL2 group and MdSOC1a and MdSOC1b are members of SOC1/AGL20 group of MADS-box genes. It has been evidentially concluded that MdSOC1a and MdSOC1b are most likely the products of an alternative splicing event in the same pre-mRNA. As another homologous gene to SOC1/AGL20, MdSOC1c was identified which was more similar to SOC1/AGL20 than were MdSOC1a and MdSOC1b and its sequences have been evaluated. Expression pattern analysis using the information of databases and RT-PCR demonstrated that MdSOC1a is expressed in stem, MdSOC1b in leaf and MdSOC1c in stem, root and bud. Two domains and one motif were distinguishable from the alignment analysis of the SOC1-like genes in various plants: MADS-box domain, K-box domain and SOC1 motif, of which the last one is special to SOC1-like genes. Classification of the SOC1-like genes revealed that MdSOC1a and MdSOC1c are at most similar to VvMADS8 and at least similar to TaAGL20 and AGL72, respectively. Finally, some suggestions have been proposed for the extension of the research in the future.