1استادیار، بخش پژوهش‌های بیوتکنولوژی، موسسه تحقیقات علوم دامی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
2دانشیار، بخش پژوهش‌های بیوتکنولوژی، موسسه تحقیقات علوم دامی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران.
چکیده
پایش میزان همخونی مرغهای بومی در ایستگاههای اصلاح نژادی، به‌دلیل انجام انتخاب ژنتیکی و عدم وجود جریان ژنی در جمعیت بسیار حایز اهمیت می‌باشد. هدف از انجام این پژوهش برآورد ضریب همخونی، بررسی روند تغییرات همخونی و ارزیابی اثرات پس‌روی ناشی از آن بر صفات اقتصادی در جمعیت مرغ بومی اصلاح‌شده اصفهان بود. صفات مطالعه‌شده شامل وزن بدن، سن بلوغ جنسی، وزن بلوغ جنسی، تعداد تخممرغ، میانگین وزن تخممرغ و وزن اولین تخممرغ بودند. در این پژوهش، دادههای جمعآوری‌شده 97272 پرنده رکوردبرداری‌شده در طی 21 نسل مورد استفاده قرار گرفتند. در مطالعه حاضر، جهت برآورد ضریب همخونی هر پرنده و اثر همخونی بر صفات به‌ترتیب از نرمافزارهای CFC و WOMBAT استفاده شد. تجزیه و تحلیل شجره نشان داد که 79/48 درصد جمعیت همخون بودند. میانگین ضرایب همخونی فردی و مادری برآوردشده به‌ترتیب برابر با 4/3 و 3/5 درصد بودند. نتایج نشان داد، به‌ازای هر یک درصد افزایش همخونی، میزان پس‌روی ناشی از آن برای صفات وزن بدن در یک روزگی، هشت هفتگی، 12 هفتگی، سن بلوغ جنسی، وزن بلوغ جنسی، تعداد تخممرغ، میانگین وزن تخممرغ و وزن اولین تخممرغ به‌ترتیب برابر با 0/800-، 2/52-، 3/51-، 0/23، 3/97-، 0/13-، 0/02 و 0/06 بود. با توجه به نتایج پژوهش حاضر، با وجود این‌که در جمعیتهای بسته تحت انتخاب ژنتیکی، نبود پرنده غیرهمخون تقریباً غیرممکن است، اما میتوان با کنترل آمیزشها در جهت کاهش همخونی، از پیدایش اثرات نامطلوب آن در جمعیت جلوگیری کرد.
1Biotechnology Research Department ,Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
2Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
چکیده [English]
Monitoring the inbreeding rate of native chickens in breeding stations is of significant importance because of planned matings and lack of gene flow in the population. This study was undertaken to estimate the inbreeding coefficient, investigate the trend of inbreeding changes and evaluate the effects of inbreeding depression on the economic traits in Isfahan improved native chicken population. The studied traits were body weight, age at sexual maturity, weight at sexual maturity, egg number, mean egg weight and egg weight at first day. In the present study, data of 97272 birds recorded during 21 generations were included. In order to estimate the inbreeding coefficient of each bird and the effect of inbreeding on the traits, CFC and WOMBAT software were used, respectively. Pedigree analysis indicated that 79.48 percent of population were inbred. The estimated average individual and maternal inbreeding coefficients were 4.3 and 3.5 percent, respectively. According to results, for every one percent increase in inbreeding, rate of inbreeding depression for the traits including the body weight in 1 day, 8 weeks and 12 weeks, age at sexual maturity, weight at sexual maturity, egg number, average weight of eggs and egg weight at first day was -0.008, -2.52, -3.51, 0.23, -3/97, -0.13, 0/02 and 0.06, respectively. Based on the results of the present study, although in closed populations under genetic selection, the absence of inbred bird is almost impossible, but, the reduction of inbreeding can be achieved by controlling the matings, which prevents the adverse effects of inbreeding in the population.
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