Application of growth stimulators can be especially effective on plantlets in vitro of tree species which are usually worse rooted and adapted in comparison with annual plants. In our work we evaluate effects of natur...Application of growth stimulators can be especially effective on plantlets in vitro of tree species which are usually worse rooted and adapted in comparison with annual plants. In our work we evaluate effects of natural (dihydroquercetin, Zircon) and synthetic growth stimulators (Melafen, Fumar, Epin-Extra) on rooting and acclimatization of common ash (Fraxinus excelsior L.) microplants. The 0.05% -?0.2% Zircon and 10-5%?Melafen enhanced in vitro rooting by 29% -?37% and 31%, respectively. Melafen also stimulated root formation faster compared to control plants. The dihydroquercetin concentration of 0.01% increased rooting by 24% and root number per shoot by 1.8 times. In vitro plants rooted on media supplemented with Melafen, Fumar and Zircon demonstrated enhanced ability to adapt to non-sterile conditions and accelerated growth. Two months after planting to the greenhouse, plants rooted on 0.01% dihydroquercetin were 45% taller than the control. Weekly spraying of plantlets with 0.02% Epin-Extra containing 24-epibrassinolid stimulated growth of uniform plants with large leaves. The obtained results support the use of growth stimulators for application in clonal micropropagation of common ash both for large-scale production of planting stock and for conservation of rare and valuable genotypes.展开更多
Anthracnose, caused by </span><i><span style="font-family:Verdana;">Colletotrichum lindemuthianum</span></i><span style="font-family:Verdana;">, is a major disea...Anthracnose, caused by </span><i><span style="font-family:Verdana;">Colletotrichum lindemuthianum</span></i><span style="font-family:Verdana;">, is a major disease of common bean and results in high yield loss. Due to the high degree of pathogenic variability of the fungus and the continual emergence of new races, genetic resistance in the host is not durable. Gene pyramiding using Marker Assisted Selection (MAS) is proposed as a viable approach to improve the durability of major genes conditioning resistance to anthracnose. In this study a common bean line Urugezi x AND 1062 susceptible to anthracnose but already improved for </span><i><span style="font-family:Verdana;">Pythium </span></i><span style="font-family:Verdana;">root rot resistance was improved for anthracnose resistance through a backcross breeding program. Genotypic selection was done in Rubilizi laboratory in Kigali, Rwanada whereas phenotypic selection was conducted in an anthracnose hotspot at Rwerere, a research Centre of the Rwanda Agricultural and Animal Resources Development Board (RAB).</span></span><span style="font-family:""><span style="font-family:Verdana;"> Analysis of variance for effect of bean varieties and anthracnose isolates on disease expression showed significant differences (p < 0.001) among varieties and isolates and for the interaction between isolates and varieties. Developed BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants were 41% of them resistant and 59% susceptible to anthracnose. However, the observed proportion of 26 resistants and 37 susceptible in BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants didn’t fit the goodness of fit of the expected proportion of 75 resistants to 25 susceptible. Only 41% of BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants inherited the resistance genes and were phenotypically resistant. Presence of SCAR-markers, SAB3 and SBB14, in the developed resistant lines </span></span><span style="font-family:Verdana;">h</span><span style="font-family:Verdana;"> suggested successful resistance transfer of anthracnose resistance genes.展开更多
文摘Application of growth stimulators can be especially effective on plantlets in vitro of tree species which are usually worse rooted and adapted in comparison with annual plants. In our work we evaluate effects of natural (dihydroquercetin, Zircon) and synthetic growth stimulators (Melafen, Fumar, Epin-Extra) on rooting and acclimatization of common ash (Fraxinus excelsior L.) microplants. The 0.05% -?0.2% Zircon and 10-5%?Melafen enhanced in vitro rooting by 29% -?37% and 31%, respectively. Melafen also stimulated root formation faster compared to control plants. The dihydroquercetin concentration of 0.01% increased rooting by 24% and root number per shoot by 1.8 times. In vitro plants rooted on media supplemented with Melafen, Fumar and Zircon demonstrated enhanced ability to adapt to non-sterile conditions and accelerated growth. Two months after planting to the greenhouse, plants rooted on 0.01% dihydroquercetin were 45% taller than the control. Weekly spraying of plantlets with 0.02% Epin-Extra containing 24-epibrassinolid stimulated growth of uniform plants with large leaves. The obtained results support the use of growth stimulators for application in clonal micropropagation of common ash both for large-scale production of planting stock and for conservation of rare and valuable genotypes.
文摘Anthracnose, caused by </span><i><span style="font-family:Verdana;">Colletotrichum lindemuthianum</span></i><span style="font-family:Verdana;">, is a major disease of common bean and results in high yield loss. Due to the high degree of pathogenic variability of the fungus and the continual emergence of new races, genetic resistance in the host is not durable. Gene pyramiding using Marker Assisted Selection (MAS) is proposed as a viable approach to improve the durability of major genes conditioning resistance to anthracnose. In this study a common bean line Urugezi x AND 1062 susceptible to anthracnose but already improved for </span><i><span style="font-family:Verdana;">Pythium </span></i><span style="font-family:Verdana;">root rot resistance was improved for anthracnose resistance through a backcross breeding program. Genotypic selection was done in Rubilizi laboratory in Kigali, Rwanada whereas phenotypic selection was conducted in an anthracnose hotspot at Rwerere, a research Centre of the Rwanda Agricultural and Animal Resources Development Board (RAB).</span></span><span style="font-family:""><span style="font-family:Verdana;"> Analysis of variance for effect of bean varieties and anthracnose isolates on disease expression showed significant differences (p < 0.001) among varieties and isolates and for the interaction between isolates and varieties. Developed BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants were 41% of them resistant and 59% susceptible to anthracnose. However, the observed proportion of 26 resistants and 37 susceptible in BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants didn’t fit the goodness of fit of the expected proportion of 75 resistants to 25 susceptible. Only 41% of BC</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> plants inherited the resistance genes and were phenotypically resistant. Presence of SCAR-markers, SAB3 and SBB14, in the developed resistant lines </span></span><span style="font-family:Verdana;">h</span><span style="font-family:Verdana;"> suggested successful resistance transfer of anthracnose resistance genes.
