تجزيه صفات زراعي مرتبط با تحمل به تنش خشكي در جمعيتهاي گندم نان

Analysis of agronomic traits related to drought tolerance in bread wheat

ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﺗﺤﻤﻞ ﺑﻪ ﺧﺸﮑﯽ و ﺷﻨﺎﺳﺎﯾﯽ ﺗﻮدهﻫﺎي ﺑﺮﺗﺮ، 438 ﻧﻤﻮﻧﻪ ژﻧﺘﯿﮑﯽ از ﮐﻠﮑﺴﯿﻮن ﮔﻨﺪم ﻧﺎن ﺑﺎﻧﮏ ژن ﮔﯿﺎﻫﯽ ﻣﻠﯽ اﯾﺮان ﺑﻪ ﻫﻤﺮاه ارﻗﺎم ﻣﺘﺤﻤﻞ ﺑﻪ ﺧﺸﮑﯽ ﮐﻮﯾﺮ، روﺷﻦ و ﻣﺎﻫﻮﺗﯽ در دو آزﻣﺎﯾﺶ آﺑﯿﺎري ﻧﺮﻣﺎل و ﺗﻨﺶ ﺧﺸﮑﯽ ﺑﺎ اﻧﺠﺎم دو آﺑﯿﺎري،ﯾﮑﯽ ﺑﻌﺪ از ﮐﺎﺷﺖ و دﯾﮕﺮي در ﻣﺮﺣﻠﻪ ﭘﺮ ﺷﺪن داﻧﻪ در ﻣﺰرﻋﻪ ﺗﺤﻘﯿﻘﺎﺗﯽ ﯾﺰد ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻧﺘﺎﯾﺞ ﺑﺮرﺳﯽ آﻣﺎرهﻫﺎي ﺗﻮﺻﯿﻔﯽ ﻧﺸﺎن داد ﮐﻪ در ﻫﺮ دو ﺷﺮاﯾﻂ ﻧﺮﻣﺎل و ﺗﻨﺶ ﺧﺸﮑﯽ، ﺻﻔﺎت ﺗﻌﺪاد ﭘﻨﺠﻪ ﺑﺎرور، وزن داﻧﻪ ﭘﻨﺞ ﺳﻨﺒﻠﻪ و ﺗﻌﺪاد ﮔﻠﭽﻪ در ﺳﻨﺒﻠﭽﻪ داراي ﺑﯿﺸﺘﺮﯾﻦ و ﺻﻔﺎت روز ﺗﺎ رﺳﯿﺪن ﮐﺎﻣﻞ و روز ﺗﺎ ﺳﻨﺒﻠﻪدﻫﯽ داراي ﮐﻤﺘﺮﯾﻦ ﺿﺮﯾﺐ ﺗﻐﯿﯿﺮات ﺑﻮدﻧﺪ. ﻣﯿﺎﻧﮕﯿﻦ ﻫﻤﻪ ﺻﻔﺎت ﺑﺠﺰ ﺗﺮاﮐﻢ ﺳﻨﺒﻠﻪ در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺧﺸﮑﯽ ﮐﺎﻫﺶ ﯾﺎﻓﺖ. ﺑﯿﺸﺘﺮﯾﻦ ﻣﯿﺰان ﮐﺎﻫﺶ ﻣﯿﺎﻧﮕﯿﻦ ﺑﻪ ﺻﻔﺎت ﺗﻌﺪاد ﭘﻨﺠﻪ ﺑﺎرور 50/61 درﺻﺪ(، وزن داﻧﻪ ﭘﻨﺞ ﺳﻨﺒﻠﻪ 44/90 درﺻﺪ( و وزن ﺻﺪ داﻧﻪ 41/78 درﺻﺪ( و ﮐﻤﺘﺮﯾﻦ ﻣﯿﺰان ﮐﺎﻫﺶ، ﺑﻪ ﻣﯿﺎﻧﮕﯿﻦ ﺻﻔﺎت روز ﺗﺎ ﺳﻨﺒﻠﻪدﻫﯽ 2/52 درﺻﺪ( و روز ﺗﺎ رﺳﯿﺪن ﮐﺎﻣﻞ 4/35 درﺻﺪ( اﺧﺘﺼﺎص داﺷﺖ. ﻧﺘﺎﯾﺞ ﺑﺮرﺳﯽ ﺿﺮاﯾﺐ ﻫﻤﺒﺴﺘﮕﯽ ﺑﯿﻦ ﺻﻔﺎت ﻧﺸﺎن داد ﮐﻪ وزن داﻧﻪ ﭘﻨﺞ ﺳﻨﺒﻠﻪ در ﻫﺮ دو ﺷﺮاﯾﻂ ﻧﺮﻣﺎل و ﺗﻨﺶ ﺧﺸﮑﯽ ﺑﺎ ﺻﻔﺎت وزن ﺻﺪ داﻧﻪ و ﺗﻌﺪاد داﻧﻪ در ﺳﻨﺒﻠﻪ داراي ﻫﻤﺒﺴﺘﮕﯽ ﻣﺜﺒﺖ و ﻣﻌﻨﯽدار ﺑﻮد. ﻧﺘﺎﯾﺞ ﺗﺠﺰﯾﻪ ﺑﻪ ﻣﺆﻟﻔﻪﻫﺎي اﺻﻠﯽ ﻧﺸﺎن داد ﮐﻪ ﭘﻨﺞ ﻣﺆﻟﻔﻪ اﺻﻠﯽ اول 80/33 و 78/92 درﺻﺪ از وارﯾﺎﻧﺲ ﮐﻞ دادهﻫﺎ را ﺑﻪ ﺗﺮﺗﯿﺐ در ﺷﺮاﯾﻂ ﻧﺮﻣﺎل و ﺗﻨﺶ ﺧﺸﮑﯽ، ﺗﻮﺟﯿﻪ ﻣﯽﮐﻨﻨﺪ. دﻧﺪروﮔﺮام ﺗﺠﺰﯾﻪ ﺧﻮﺷﻪاي ﺑﺮاﺳﺎس ﺻﻔﺎت ارزﯾﺎﺑﯽ ﺷﺪه در ﺷﺮاﯾﻂ ﺗﻨﺶ ﺧﺸﮑﯽ، ﻧﻤﻮﻧﻪﻫﺎي ژﻧﺘﯿﮑﯽ را ﺑﻪ ﺳﻪ ﮔﺮوه ﺗﻘﺴﯿﻢ ﻧﻤﻮد ﮐﻪ در ﻫﺮ ﮔﺮوه، ﯾﮑﯽ از ارﻗﺎم ﺷﺎﻫﺪ ﻗﺮار ﮔﺮﻓﺖ. ﺑﺎ ﻣﻘﺎﯾﺴﻪ ﻣﯿﺎﻧﮕﯿﻦ ﺳﻪ ﮔﺮوه ﻣﺬﮐﻮر ﻣﺸﺨﺺ ﺷﺪ ﮐﻪ ﻫﺮ ﮔﺮوه از ﻟﺤﺎظ ﺑﺮﺧﯽ از ﺻﻔﺎت ﻧﺴﺒﺖ ﺑﻪ ﮔﺮوهﻫﺎي دﯾﮕﺮ ﺑﺮﺗﺮي دارد. ﻣﺠﻤﻮع اﯾﻦ ﻧﺘﺎﯾﺞ ﻧﺸﺎن دﻫﻨﺪه ي وﺟﻮد ﺗﻨﻮع ﻗﺎﺑﻞ ﺗﻮﺟﻪ در ﻣﻮاد ژﻧﺘﯿﮑﯽ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﺑﻮد. ﻫﻤﭽﻨﯿﻦ از ﻟﺤﺎظ ﻫﺮ ﯾﮏ از ﺻﻔﺎت اﻧﺪازهﮔﯿﺮي ﺷﺪه، ﺗﻌﺪادي ﻧﻤﻮﻧﻪ ژﻧﺘﯿﮑﯽ ﺑﺮﺗﺮ از ارﻗﺎم ﺷﺎﻫﺪ ﺷﻨﺎﺳﺎﯾﯽ ﺷﺪ ﮐﻪ در ﺑﺮﻧﺎﻣﻪﻫﺎي اﺻﻼﺣﯽ ﺑﺮاي ﺗﺤﻤﻞ ﺑﻪ ﺗﻨﺶ ﺧﺸﮑﯽ ﻗﺎﺑﻞ اﺳﺘﻔﺎده ﻣﯽﺑﺎﺷﻨﺪ.

In order to study drought tolerance and identification of superior populations, 438 accessions from bread wheat collection of the National Plant Gene Bank of Iran along with tolerant check cultivars Kavir, Roshan, and Mahooti were investigated in Yazd research field under two irrigation regimes including normal one and drought stress experiment performed by twice irrigations, one immediately after sowing and the other over grain filling period. The results of descriptive statistics showed that in both normal and drought conditions, number of tillers, seed weight of five spikes and number of florets in spikelet had the highest and traits day to full maturity and day to heading had the lowest coefficient of variation. Mean of all traits except spike density decreased under drought stress conditions. The highest mean reduction was observed for the number of tillers (50.61%), grain weight of five spikes (44.90%) and 100 grain weight (41.78%) and the lowest amount of reduction belonged to the average of days to heading (2.52%) and day to full maturity (4.35%). Correlation coefficients between traits showed that grain weight of five spikes in both normal and stress conditions had positive and significant correlations with 100 grain weight and seed number per spike. The results of principal component analysis under normal and drought stress conditions showed that the first five components justified 80.33% and 78.92% of the total variance, respectively. Dendrograms of cluster analysis developed based on the traits evaluated under drought stress condition divided the studied accessions into three groups, each of which comprising one of the check cultivars. By comparing the mean of the three groups, it was determined that each group excels in some of the traits compared to the other group. The total results indicate a significant variation in genetic material under study. Moreover, a number of accessions were found to be superior to the check cultivars for each of the measured traits which can be used in future breeding programs for drought tolerance