ارزیابی و انتخاب ژنوتیپ‌های برتر عدس (lens culinaris medik) دیم در مناطق سرد کشور با الگوی خطوط مرزی صفات زراعی

شناخت صفات مهم گیاهی و تاثیر آن بر عملکرد دانه از ابزارهای اصلی به نژادگران عدس در انتخاب و معرفی ارقام سازگار با مناطق دیم می باشد. برای تعیین حد و دامنه بهینه صفات زراعی عدس دیم، بانک اطلاعاتی گسترده ای از ایستگاه‌های تحقیقات کشاورزی دیم مناطق سرد کشور (مراغه، زنجان، اردبیل و شیروان) با 8300 ژنوتیپ به مدت 20سال (1395-1375) جمع آوری شد. حد و دامنه بهینه صفات زراعی با استفاده از دو روش خطوط مرزی و میانگین‌گیری از جامعه دارای عملکرد بالا تعیین شد. حد بهینه ارتفاع بوته، وزن100دانه، تعداد روز از کاشت تا گلدهی و رسیدگی فیزیولوژیک و طول دوره پُرشدن دانه با خطوط مرزی به‌ترتیب 27.8 سانتی متر، 5.4 گرم، 55.4 روز، 92.6 روز و 33.8 روز و با روش میانگین‌گیری به‌ترتیب 23.7 سانتی متر، 4.9 گرم، 62.0 روز، 92.6 روز و 30.7 روز تعیین شد. هر دو روش حد تعداد روز از کاشت تا رسیدگی فیزیولوژیک را یکسان برآورد نمودند. در حالی که در تعیین دامنه بهینه بین دو روش، تفاوت معنی داری وجود داشت و روش خطوط مرزی دامنه آن را به طور میانگین سه برابر گسترده تر برآورد نمود. تجزیه به مولفه های اصلی، مهم‌ترین صفات برای گزینش ارقام عدس دیم را تعداد روز از کاشت تا گلدهی و رسیدگی فیزیولوژیک تشخیص داد. با توجه به دقّت بالا در برآورد حد و دامنه بهینه صفات و انطباق بیشتر نتایج آن با ارقام معرفی‌شده در این مناطق، استفاده از روش خطوط مرزی برای انتخاب ژنوتیپ‌های برتر توصیه می‌شود.

identification and selection of superior dryland lentil (lens culinaris medik) genotypes using boundary lines in iran cold areas

introduction pulse crops play important role in supplying human food needs. lentil (lens culinaris medik.) is probably the oldest grain legume to be domesticated and one of the most important pulse crops worldwide due its nutritional characteristics. lentil is an integral part of dryland agriculture, mainly because of its ability to thrive comparatively well under water-limiting environments. as a result, the crop which provides protein-rich food and animal feed is largely grown under rainfed conditions. the major lentil producing countries are india, canada, turkey, usa, nepal, australia, syria, china, bangladesh, iran, etc. iran ranked fourth in area after india, turkey and canada and ninth in the production. the aim of any breeding program working for unpredictable and rainfed environments is to develop varieties with high and stable yields. breeders take advantage of the selection for several traits to achieve maximum economic yield. the selection of genotypes based on indices using yield components was used by breeders for a long time. breeders believe that obtaining a linear function for measurable traits could lead the selection of genotypes with better genetic values, but a need to include economic value and weights in this function express by many researchers. simultaneous selection using characteristics with important and heritable economic values is more effective. crop yield is a function of multiple variables inter-related to each other and can not be defined only by a single-variable equation. one of the most effective of these methods is boundary lines. feiziasl et al (2003 and 2010) used this method for the first time to determine the optimum levels of plant (dryland wheat) characteristics and yield stability analysis. in this paper, “boundary lines” and averaging methods and are used to determine optimum levels for some traits of dryland lentil in cold areas. materials and methods more than 8300 data for each trait were collected from national and international trials conducted under rainfed conditions in maragheh, zanjan, ardabil and shirvan (north khorasan province) dari experiment stations 20 years (1996-2016). the traits considered in the analysis were: days to heading, days to physiological maturity, grain filling period, plant height, 100 seed weight and grain yield. the excel software was used to develop a scatter diagram showing the relationship between each trait with grain yield in each location. two methods were used to determine the optimum value for a given characteristic. one is based on the boundary lines method where the maximum grain yield and the optimum value for the trait considered coincide with the crossing point of the two boundary lines. “boundary lines” method was used to determine the maximum limits of each crop characteristic. the scatter diagram is surrounded by two regression lines, one on the left and the other on the right called boundary lines. then maximum yield is obtained at the intersection of both boundary lines. the other approach, called averaging method, is based on subdividing the data into two groups: high and low yielding groups. results and discussion the boundary lines method allowed the determination of optimum levels for days to flowering, days to physiological maturity, duration of grain filling, plant height and 100 seed weight which were 55.4 days, 92.6 days, 33.8 days, 27.8 centimeters and 5.4 grams, respectively. by averaging of high yielding group method optimums for days to flowering, days to physiological maturity, duration of grain filling, plant height and 100 seed weight characteristics were 62.0 days, 92.6 days, 30.7 days, 23.7 centimeters, 4.9 grams, respectively. these optimums were closely equivalent to those determined using the averaging method for one days to physiological maturity characteristic.