Haile Bewuketu, Tesfaye Bizuayehu, Olango Temesgen Magule
Hawassa University, School of Plant and Horticulture Science, P.O. Box 05, Hawassa, Ethiopia.
Mizan-Tepi University, Department of Horticulture, P. O. Box 260, Mizan-Aman, Ethiopia.
Heliyon. 2021 Nov 16;7(11):e08416. doi: 10.1016/j.heliyon.2021.e08416. eCollection 2021 Nov.
The declining trends in crop wild relative genetic resources in many crop centers of origins including Ethiopia require short and long-term conservation strategies. Enset () is arguably the most important cultivated food security crop of Ethiopia with dwindling wild stocks. The cultivated enset is propagated clonally through adventitious bud sprouting from the corm after the distraction of the apical meristem. Shoot regeneration in the cultivated enset has been induced by humans and has not been observed to occur naturally. The technique of shoot induction has not been extended to the wild enset. To determine whether the capacity for shoot regeneration existed in wild enset and optimize the technique, a series of experiments were conducted. These involved: (i) sucker production from corms of wild enset with and without apical meristem removal; (ii) sprouting capacity of corms ranging 22-49 cm diameter, with removed apical meristem; and (iii) a factorial experiment involving two populations of wild enset (from and localities in Sheka zone), two ways of preparing or cutting the corms: and , i.e. cutting the pseudostem at the corm junction and cutting it at 25-30 cm height, respectively, and three extents of parting the corm (whole, half, and quarter) using corms with a diameter of 45 ± 2.9 cm. The experiments revealed that wild enset can be successfully propagated vegetatively in the same way as the cultivated enset. It also revealed that the regeneration process involved callus formation and adventurous bud proliferation from corms only after the apical meristem was removed. Corms of different sizes varied in their capacity for regeneration significantly with a linear increase in regeneration frequency with corm size. With a one cm increase in corm diameter, regeneration frequency increased by 3.138 %. The two populations of wild enset showed non-significant differences in regeneration capacity; however, the achieved regeneration was generally analogous to that observed among cultivated enset clones: whole corms resulted in a longer time to emergence and fewer sucker per corm than split corms. Specifically, halved corms emerged significantly (p < 0.05) earlier (71 ± 9 and 75 ± 7 days, for and populations, respectively) than whole corms (120 days). Regeneration frequency was higher (75-100%) for split than for whole corms (33-56%). The highest rate of suckering (94 ± 14 per corm) was achieved from quarter corms prepared by cutting the pseudo-stem at the junction. In conclusion, the adventitious bud propagation technique developed by farmers to propagate the cultivated enset can successfully be used for the clonal regeneration of wild enset. We recommend the adoption of this shoot induction to conserve and maintain the rapidly eroding wild enset genetic resources in Ethiopia. In addition, wild enset plants with promising characteristics may be fixed using the method to enrich the gene pool of the cultivated enset.
在包括埃塞俄比亚在内的许多作物起源中心,作物野生近缘种遗传资源呈下降趋势,这需要制定短期和长期的保护策略。埃塞俄比亚蕉(Enset)可以说是该国最重要的用于保障粮食安全的栽培作物,但其野生种群数量正在减少。栽培的埃塞俄比亚蕉是通过顶端分生组织被破坏后球茎上不定芽的萌发进行无性繁殖的。栽培埃塞俄比亚蕉的芽再生是由人工诱导的,尚未观察到自然发生的情况。芽诱导技术尚未应用于野生埃塞俄比亚蕉。为了确定野生埃塞俄比亚蕉是否具有芽再生能力并优化该技术,进行了一系列实验。这些实验包括:(i)去除和不去除顶端分生组织的野生埃塞俄比亚蕉球茎的吸芽产生;(ii)直径为22 - 49厘米、去除顶端分生组织的球茎的发芽能力;(iii)一项析因实验,涉及两个野生埃塞俄比亚蕉种群(来自谢卡地区的两个地点),两种球茎处理或切割方式:分别是在球茎连接处切割假茎和在25 - 30厘米高度处切割假茎,以及使用直径为45 ± 2.9厘米的球茎进行三种程度的球茎分割(完整、一半和四分之一)。实验表明,野生埃塞俄比亚蕉可以像栽培埃塞俄比亚蕉一样成功地进行无性繁殖。实验还表明,再生过程仅在去除顶端分生组织后才涉及愈伤组织形成和球茎上不定芽的增殖。不同大小的球茎再生能力差异显著,再生频率随球茎大小呈线性增加。球茎直径每增加一厘米,再生频率增加3.138%。两个野生埃塞俄比亚蕉种群的再生能力差异不显著;然而,所实现的再生情况通常与栽培埃塞俄比亚蕉克隆中观察到的情况相似:完整球茎比分割球茎出苗时间更长且每个球茎的吸芽更少。具体而言,对半分割的球茎出苗时间显著更早(p < 0.05)(两个种群分别为71 ± 9天和75 ± 7天),而完整球茎为120天。分割球茎的再生频率(75 - 100%)高于完整球茎(33 - 56%)。通过在连接处切割假茎制备的四分之一球茎吸芽率最高(每个球茎94 ± 14个)。总之,农民开发的用于繁殖栽培埃塞俄比亚蕉的不定芽繁殖技术可以成功地用于野生埃塞俄比亚蕉的克隆再生。我们建议采用这种芽诱导方法来保护和维持埃塞俄比亚迅速减少的野生埃塞俄比亚蕉遗传资源。此外,可以使用该方法固定具有优良特性的野生埃塞俄比亚蕉植株,以丰富栽培埃塞俄比亚蕉的基因库。