پديد آورندگان :
مرتضوي، الياس سازمان تحقيقات آموزش و ترويج كشاورزي - پژوهشكده بيوتكنولوژي كشاورزي ايران - بخيش مهندسي ژنتيك و ايمني زيستي , عرب سلماني، مرتضي سازمان تحقيقات آموزش و ترويج كشاورزي - مركز تحقيقات آموزش و ترويج كشاورزي استان تهران - بخش تحقيقات پنبه، ورامين , حسن زاده خانكهداني، حامد مركز تحقيقيات و آموزش كشاورزي و منابع طبيعي هرمزگان - بخش تحقيقات زراعي و باغي
كليدواژه :
پنبه , شاخص خسارت آفت , لاين ترا ريخته , مقاومت , Gossypium hirsutum
چكيده فارسي :
به منظور ارزيابي ميزان مقاومت سه لاين تراريخته پنبه در برابر آفات بالپولكدار در شرايط مزرعه‌اي و نيز بررسي امكان استفاده از اين ارقام در برنامه‌هاي آزادسازي رقم، پژوهشي در قالب طرح بلوك‌هاي كامل تصادفي در هشت تكرار در استان هرمزگان، ميناب اجرا شد. مواد گياهي شامل دو لاين تراريخته حاوي رويداد تراريزشي MON531 موسوم به لاين‌هاي A و B، يك رقم تراريخته تجاري حاوي تراژن cryIAc به نام CRI به همراه رقم غيرتراريخته ورامين به عنوان شاهد منفي بودند. در اين آزمايش مجموعه‌اي از صفات شامل عملكرد، تعداد غوزه، درصد آلودگي غوزه، درصد آلودگي برچه و درصد آسيب به غوزه اندازه‌گيري شده و در نهايت شاخص خسارت نيز مورد محاسبه قرار گرفت. نتايج آناليزهاي ارزيابي‌هاي وضعيت مقاومت نشان داد كه لاين‌هاي تراريخته مورد آزمايش از نظر صفات مورد بررسي تفاوت معني‌دار دارند. هم‌چنين، دو لاين تراريخته A و B ضمن داشتن بالاترين عملكرد، داراي كمترين آلودگي و كمترين خسارت از آفات بالپولكدار بوده و رقم غيرتراريخته ورامين، بيشترين خسارت و آلودگي را نشان داد. هم‌چنين، رقم تراريخته CRI از نظر تمامي خصوصيات بين دو گروه تراريخته و غيرتراريخته قرار گرفت. در مجموع نتايج اين پژوهش نشان داد كه در بين لاين‌هاي تراريخته مورد مطالعه، دو لاين تراريخته A و B داراي مكانيسم مقاومت بالاتري در برابر آفات بالپولكدار هستند و از اين رو، امكان استفاده از آنها در برنامه‌هاي آزادسازي رقم وجود دارد.
چكيده لاتين :
Introduction: The most threatening factor in cotton production worldwide is Lepidoptera pests. The pest
management using chemicals imposes huge costs and environmental side effects. Introduction of genetic
engineering as a modern technology has opened a new insight for investigators to control the pests through
transgenic pest resistant varieties. Cotton was the first transgenic crop which received cry genes, and introduced
to farmers after numerous field trials. The field trials on evaluation of transgenic lines are a complex process in
three levels comprising mini, mid and large scale trials, but the first step in this process is evaluation of transgene
in the field condition along with considering other important crop properties. There are several Lepidoptera pests
causing damage to cotton in nearly all cotton producing areas worldwide. However, bollworm (Helicoverpa
armigera Hübner) and spiny cotton bollworms (Earias vittella Fabricius and Earias insulana Boisduval) are the
most the most important pests in Iran. Also, there are many biotypes among different geographical populations.
This fact implies that the transgenic lines should be tested in different locations within a country. A number of
research works has been conducted to produce transgenic cotton via both modern biotechnology and traditional
backcrosses in Iran. As a result, some different transgenic lines harbouring cry genes were produced. Primary
evaluation of these transgenic lines was resulted to a few lines exhibited the most resistance characters against
the pests. More precise evaluation of the lines for pest resistance traits and yield was done in this study.
Materials and Methods: Three transgenic lines harbouring cryIAc gene comprising A, B and CRI lines
along with a non-transgenic variety as negative control (Varamin) were used in the experiment. The experiment
was conducted in a Lepidoptera pest affected farm at Minab, Hormozgan from June to July of 2015. A complete
randomized block design with eight replications was adopted as the statistical model. Each plot consisted of
eight lines with 8 meters length in which the distance between lines were 80 cm. All agricultural operations
including irrigation, fertilizer and weeding were carried out according to local recommendations. During
growing season, some properties related to the pest resistance including number of bolls per plant, percentage of
contaminated bolls, percentage of contaminated locule, and percentage of boll injuries were recorded, and
damage index was then calculated. The varieties yield was recorded as well. All traits were recorded on two
separate dates i.e. June and July, 2015. The data were analyzed using SAS software according to the adopted
statistical model.
Results and Discussion: Analysis of variance showed that all recorded traits in the experiment were
significant for cultivars effect, except for boll injuries percentage. Primarily, the current results demonstrate that
all cultivars were exposed to the pest equally. Other traits including number of bolls per plant, percentage of
contaminated bolls, percentage of contaminated locule, damage index and yield differed significantly between
the cultivars. The mean comparison for number of boll per plant showed that transgenic A and B (transgenic)
lines produced and kept the most boll number, and CRI transgenic line and Varamin cultivar ranked as the
second. This trait is very important, because it not only acts as a yield component, but also involves in resisting
against pests. The mean comparison for contaminated boll and contaminated locule traits showed that nontransgenic Varamin cultivar had the largest contamination amounts. In contrast, transgenic A and B lines
exhibited the least contamination for both traits.
The most important trait expressing resistance is damage index. The lowest damage index was calculated for
B line (0.69 and 0.46% in June and July, respectively) and A line (0.75 and 0.56% in June and July,
respectively), and CRI line ranked as the second (2 and 5%). Meanwhile, the damage index of Varamin cultivar
in this experiment was 3.8 and 11.5% in June and July, respectively. The damage index for A and B transgenic
lines in the first and second recording show a downward pattern in contrast to CRI line and Varamin cultivar.
Hence, Lepidoptera pests does not succeed in feeding on the A and B lines. Moreover, A and B lines exhibited
the best yield (5041 and 4466 kg/ha, respectively), and the CRI line ranked as the second (3382 kg/ha). The
Varamin cultivar yield was 3071 kg/ha which was the least record.
Conclusion: In general, two out of three transgenic lines comprising A and B lines had the best yield, the
minimum contaminations and injuries by Lepidoptera pests. Varamin cultivar, as non-transgenic control line
showed the least tolerance and yield and the CRI cultivar were ranked between the superior transgenic and nontransgenic lines. Both A and B transgenic lines have proper agronomic traits and the best resistance characters
against Lepidotera pests. It can be concluded that these lines, as the first Iranian transgenic varieties, can be used
for registration and commercialization.
