The plants of hybrid wheatgrass （A. cristatum×A. desertorum cv. Hycrest-Mengnong） were directly induced from embryogenic callus regenerated from immature inflorescence. Immature inflorescence was cultured on im...The plants of hybrid wheatgrass （A. cristatum×A. desertorum cv. Hycrest-Mengnong） were directly induced from embryogenic callus regenerated from immature inflorescence. Immature inflorescence was cultured on improved MS medium containing 2.0-3.0 mg L^-1 2,4-D to regenerate callus. The calli were then transferred to hormone-free MS medium for differentiation and 1/2 MS medium for rooting. Results showed that callus initiation frequency was 83.4% and plant regeneration frequency was 59.6%. Phosphinothricin acetyltransferase （bar） gene was transformed into the hybrid wheatgrass by particle bombardment. Resistant callus was obtained using selecting agent, herbicide glufosinate of 0.5 mg L^-1, and some transgenic plants were recovered in vitro. The transgenic plants were identified by PCR and Southern blot analysis and these plants developed normally in the glufosinate medium, whereas the nontransgenic plants did not. The results demonstrated that bar cDNA integrated into the genomic DNA of the transgenic plants. The transgenic frequencies of bar gene were 1.1%.展开更多
对分布于我国不同地区的冰草属(Agropyron Gaertn.)4个种的33份材料进行了花粉母细胞减数分裂期染色体行为观察。发现含 B 染色体的材料主要集中在沙芦草(A.mongolicumKeng,2n=2x=14)中。在沙生冰草(A.deseriorum〈Fi sch.〉Schult.,2n=...对分布于我国不同地区的冰草属(Agropyron Gaertn.)4个种的33份材料进行了花粉母细胞减数分裂期染色体行为观察。发现含 B 染色体的材料主要集中在沙芦草(A.mongolicumKeng,2n=2x=14)中。在沙生冰草(A.deseriorum〈Fi sch.〉Schult.,2n=4x=28)中有40%的材料含 B 染色体。而在四倍体冰草(A.cristatum〈L.〉Gaertn.,2n=4x=28)和根茎冰草(A.michnoi Roshev.,2n=4x=28)中未找到含 B 染色体的材料。偶数 B 染色体间的配对通常发生在终变期,而奇数 B 染色体间的配对通常在中期 I。B 染色体在后期 I的分离是随机的。落后 B 染色体的分离,一般是通过本身的提前分裂以染色单体的形式趋向两极。含有较高数目的 B 染色体有提高 A 染色体间配对和交叉频率的作用。讨论了 B 染色体的存在与倍性水平间的关系以及 B 染色体间的同源性等问题。展开更多
对冰草根际分离获得的蟋蟀草平脐蠕孢（Bipolaris eleusineaJ.H.Peng et J.Y.Lu）的形态特征、培养性状及生物学特性进行研究,以期了解牧草根部平脐蠕孢菌的生长发育特点,并为该菌引起的牧草根病防治提供依据。结果表明：蟋蟀草平脐蠕...对冰草根际分离获得的蟋蟀草平脐蠕孢（Bipolaris eleusineaJ.H.Peng et J.Y.Lu）的形态特征、培养性状及生物学特性进行研究,以期了解牧草根部平脐蠕孢菌的生长发育特点,并为该菌引起的牧草根病防治提供依据。结果表明：蟋蟀草平脐蠕孢分生孢子萌发的温度范围为5℃~40℃,适宜温度20℃~30℃;在各酸度下均能萌发,最适为pH 6.47;其分生孢子的萌发需要液态水,在相对湿度100%时分生孢子萌发率仅为3.2%,而相对湿度低于100%时孢子不萌发;低稀释倍数的土壤悬液、麦根浸出液、羊粪浸出液和蔗糖溶液[0]及高稀释倍数的麦根液和羊粪液均抑制孢子萌发,但高稀释倍数的土壤液和蔗糖液能促进孢子萌发;且孢子萌发对光不敏感。蟋蟀草平脐蠕孢菌丝生长的温度范围为10℃-40℃,最适25℃;碳源中D-木糖、氯醛糖对蟋蟀草平脐蠕孢菌生长具有明显抑制作用,而蔗糖、甘露糖和D-果糖对蟋蟀草平脐蠕孢菌丝生长具有明显促进作用;氮源中硝酸钠、亮氨酸对蟋蟀草平脐蠕孢菌丝的生长具有促进作用,而尿素等9种氮源均有抑制作用,并且此菌在含有各种碳、氮源的培养基上的菌落形态有差异。在国内首次报道此菌侵染冰草（Agropyron cristatum）,为一新寄主植物。展开更多
文摘The plants of hybrid wheatgrass （A. cristatum×A. desertorum cv. Hycrest-Mengnong） were directly induced from embryogenic callus regenerated from immature inflorescence. Immature inflorescence was cultured on improved MS medium containing 2.0-3.0 mg L^-1 2,4-D to regenerate callus. The calli were then transferred to hormone-free MS medium for differentiation and 1/2 MS medium for rooting. Results showed that callus initiation frequency was 83.4% and plant regeneration frequency was 59.6%. Phosphinothricin acetyltransferase （bar） gene was transformed into the hybrid wheatgrass by particle bombardment. Resistant callus was obtained using selecting agent, herbicide glufosinate of 0.5 mg L^-1, and some transgenic plants were recovered in vitro. The transgenic plants were identified by PCR and Southern blot analysis and these plants developed normally in the glufosinate medium, whereas the nontransgenic plants did not. The results demonstrated that bar cDNA integrated into the genomic DNA of the transgenic plants. The transgenic frequencies of bar gene were 1.1%.
文摘对分布于我国不同地区的冰草属(Agropyron Gaertn.)4个种的33份材料进行了花粉母细胞减数分裂期染色体行为观察。发现含 B 染色体的材料主要集中在沙芦草(A.mongolicumKeng,2n=2x=14)中。在沙生冰草(A.deseriorum〈Fi sch.〉Schult.,2n=4x=28)中有40%的材料含 B 染色体。而在四倍体冰草(A.cristatum〈L.〉Gaertn.,2n=4x=28)和根茎冰草(A.michnoi Roshev.,2n=4x=28)中未找到含 B 染色体的材料。偶数 B 染色体间的配对通常发生在终变期,而奇数 B 染色体间的配对通常在中期 I。B 染色体在后期 I的分离是随机的。落后 B 染色体的分离,一般是通过本身的提前分裂以染色单体的形式趋向两极。含有较高数目的 B 染色体有提高 A 染色体间配对和交叉频率的作用。讨论了 B 染色体的存在与倍性水平间的关系以及 B 染色体间的同源性等问题。
