An In Vitro Germination Technique for Some Stone Fruit Species: the Embryo Isolated from Cotyledons Successfully Germinated without Cold Pre-treatment of Seeds

Abstract

<jats:p>Seeds of temperate fruit species need a long time to germinate as a result of their requirement of stratification or cold treatment. Therefore, fast and uniform germination techniques are desirable and important for fruit tree propagation and especially for breeding studies. The effects of combinations of benzylaminopurine (BAP) and gibberellic acid (GA<jats:sub>3</jats:sub>) on in vitro embryo germination of apricot, peach, and wild cherry were determined without seed cold pretreatment. The results showed that no germination was recorded in all the seeds with testa. In the seeds without testa, no germination (wild cherry) or limited germination (less than 10%) was recorded. When the embryos separated from cotyledons were cultured, successful germination was obtained for all species. In general, the addition of different combinations of BAP and GA<jats:sub>3</jats:sub> into the Murashige and Skoog (MS) medium significantly increased the germination ratios of embryos without cotyledons in all species. For wild cherry, the best treatment (66.7% germination) was MS media containing 0.5 mg·L<jats:sup>−1</jats:sup> BAP + 2.0 mg·L<jats:sup>−1</jats:sup> GA<jats:sub>3</jats:sub> or 0.5 mg·L<jats:sup>−1</jats:sup> BAP + 4.0 mg·L<jats:sup>−1</jats:sup> GA<jats:sub>3</jats:sub>. For peach, the best treatment (86.7% germination) was MS medium supplemented with 0.5 mg·L<jats:sup>−1</jats:sup> BAP + 3.0 mg·L<jats:sup>−1</jats:sup> GA<jats:sub>3</jats:sub>. For apricot, the best treatment (93.3%) was MS media containing 0.5 mg·L<jats:sup>−1</jats:sup> BAP + 3.0 mg·L<jats:sup>−1</jats:sup> GA<jats:sub>3</jats:sub>, 1.0 mg·L<jats:sup>−1</jats:sup> BAP + 1.0 mg·L<jats:sup>−1</jats:sup> GA<jats:sub>3</jats:sub>, or 1.0 mg·L<jats:sup>−1</jats:sup> BAP + 2.0 mg·L<jats:sup>−1</jats:sup> GA<jats:sub>3</jats:sub>.</jats:p>

The Control of Apricot Seed Dormancy and Germination by Low Temperature Treatments

“…Principle commercial crops in this genus include peaches, nectarines, plums, prunes, apricots, cherries, and almonds. Seeds of stone fruits do not germinate immediately after harvest and a period of after ripening is essential for certain chemical and other changes to take place in the seed and for dormant embryo to grow [1]. Seed dormancy is a physiological phenomenon in plants, which is caused by external or internal factors, and prevents of seeds germination, even in optimal conditions.…”

“…In this respect, García-Gusano et al [3] reported two independent dormancies in seeds of stone fruit a physical (external) and embryo (internal) dormancy which are essential for better survival and establishment of seedlings in the field. Seeds of temperate fruit species need a long time to germinate as a result of their requirement of stratification or cold treatment [1,4]. Seeds of temperate fruit species do not germinate as a result of seed dormancy even if conditions such as water, temperature, and oxygen are suitable for germination.…”

“…Scarification can be done either mechanically or chemically [2]. Several researchers working on breaking dormancy such as Rady and El-Yazal [15], Rady and El-Yazal [16] El-Yazal and Rady [17] El-Yazal et al [18] El-Yazal and Rady [19] El-Yazal and Rady [20] El-Yazal et al [21] El-Yazal et al [22] El-Yazal et al [23] El-Yazal et al [24] El-Yazal et al El-Yazal [26] on buds and Şan [1], Mark [27], Keun et al [28], Pliszko and Kostrakiewicz-Gierałt [29], Pliszko and Kostrakiewicz-Gierałt [30] Pliszko and Kostrakiewicz-Gierałt [31] Górnik et al [32] on seeds. The beneficial effect of stratification on seed germination was studied by Seng and Cheong [33] Yan and Chen [34] Guo et al [35].…”

Chilling-Requirement Release of Seed and Bud Dormancy in Apricot

“…Seeds of stone fruits do not germinate immediately after harvest and a period of after ripening is essential for certain chemical and other changes to take place in the seed and for dormant embryo to grow [21,22,23]. Seed dormancy is a physiological phenomenon in plants, which is caused by external or internal factors, and prevent of seeds germination, even in optimal conditions.…”

“…Seed dormancy may be caused due to hard seed coat, immature embryo, rudimentary embryo and inhibitors materials [23,24]. Seeds of temperate fruit species need a long time to germinate as a result of their requirement of stratification or cold treatment [21,23,25]. Seeds of temperate fruit species do not germinate as a result of seed dormancy even if conditions such as water, temperature, and oxygen are suitable for germination.…”