Embryo Incision as a New Technique for Double Seedling Production of Indonesian Elite Coconut Type âKopyorâ

One of the present major limitations of seedling production of kopyor type coconut using embryo culture is that only one seedling can be produced from a single embryo. Therefore, we report on the development of a new breakthrough technique for the production of double seedlings from a single embryo. The technique consists of four steps, viz. (i) germination; (ii) incision; (iii) splitting; and (iv) recovery. A histological study was carried out on the development of the halved embryo into a new shoot. The best recovery process was obtained when the incised embryo was split into two and recovered into Murashige and Skoog (MS) medium supplemented with 2 μM IBA and 15 μM kinetin. Following this protocol, an average of 56 shoots was successfully recovered from 30 zygotic embryos. The histological study also revealed that the meristem tissue of the halved embryo was able to produce a new meristem and primordial leaf. Most of the shoots then went on to produce normal seedlings and could be acclimatized successfully after having developed 2 or 3 leaves. This protocol is useful for routine seedling production of the kopyor-type coconut

Embryo Incision as a New Technique for Double Seedling Production of Indonesian Elite Coconut Type âKopyorâ

One of the present major limitations of seedling production of kopyor type coconut using embryo culture is that only one seedling can be produced from a single embryo. Therefore, we report on the development of a new breakthrough technique for the production of double seedlings from a single embryo. The technique consists of four steps, viz. (i) germination; (ii) incision; (iii) splitting; and (iv) recovery. A histological study was carried out on the development of the halved embryo into a new shoot. The best recovery process was obtained when the incised embryo was split into two and recovered into Murashige and Skoog (MS) medium supplemented with 2 μM IBA and 15 μM kinetin. Following this protocol, an average of 56 shoots was successfully recovered from 30 zygotic embryos. The histological study also revealed that the meristem tissue of the halved embryo was able to produce a new meristem and primordial leaf. Most of the shoots then went on to produce normal seedlings and could be acclimatized successfully after having developed 2 or 3 leaves. This protocol is useful for routine seedling production of the kopyor-type coconut

Ex vitro rooting using a mini growth chamber increases root induction and accelerates acclimatization of Kopyor coconut (Cocos nucifera L.) embryo culture-derived seedlings

Ex vitro rooting using a mini growth chamber to maintain relative humidity has been used to mass produce true-to-type Kopyor coconut (Cocos nucifera L.) seedlings through embryo culture. This new process was found to (1) improve the proportion of seedlings successfully transferred to soil (from 40 to 90% for seedlings with roots); (2) achieve this step in the shortest time possible (a reduction from 10 to 4 mo in in vitro culture); (3) improve root formation using indolebutyric acid (IBA; an improvement in the number of primary roots from 2 to 5); and (4) improve the vigor of seedlings ex vitro (improvements of fresh weight, shoot length, number of opened leaves, leaf thickness, amount of epicuticular wax, and stomatal density). The best ex vitro rooting and rapid acclimatization protocol was obtained when 4-mo-old seedlings with two opened leaves were kept in the mini growth chamber for 3 mo before being transferred into soil, and when the mini growth chamber was flooded with a quarter strength hybrid embryo culture (HEC) medium with 1 μM IBA but depleted of vitamins and sugar. This protocol was efficient in delivering high-value Kopyor seedlings to the field (90% success rate), with a decreased risk of contamination and lower labor cost. The improved process was found applicable to both tall and dwarf Kopyor and other coconut types