BACKGROUND
Asparagus (Asparagus officinalis L.) is a popular vegetable because it is one of the
first field crops to be harvested in spring and it can provide both growers and consumers
with an early-season fresh commodity. As a dioecious crop, asparagus is inevitably
cross-pollinating. Male and female flowers are borne on different plants. Generally,
male plants have more commercial advantages over the female plants. They have higher
productivity [Falloon and Nikoloff 1986] and produce more stalks [Gonzalez Castanon
1990]. Female plants live shorter, emerge later in spring and produce fruits. These fruits
compete with the crowns and roots for nutrients. All-male hybrids produce higher yield,
have better disease tolerance, greater longevity and definitely no seed is produced [Falloon
1982]. In order to obtain all-male hybrids, the production of supermale is the key.
Nevertheless, supermale rarely exists in nature. Therefore, supermale plants are produced
through pollen or anther culture [Doré 1977]. In asparagus in vitro culture, the
development of storage roots is essential. Plantlets without well developed storage roots
BACKGROUND
Asparagus (Asparagus officinalis L.) is a popular vegetable because it is one of the
first field crops to be harvested in spring and it can provide both growers and consumers
with an early-season fresh commodity. As a dioecious crop, asparagus is inevitably
cross-pollinating. Male and female flowers are borne on different plants. Generally,
male plants have more commercial advantages over the female plants. They have higher
productivity [Falloon and Nikoloff 1986] and produce more stalks [Gonzalez Castanon
1990]. Female plants live shorter, emerge later in spring and produce fruits. These fruits
compete with the crowns and roots for nutrients. All-male hybrids produce higher yield,
have better disease tolerance, greater longevity and definitely no seed is produced [Falloon
1982]. In order to obtain all-male hybrids, the production of supermale is the key.
Nevertheless, supermale rarely exists in nature. Therefore, supermale plants are produced
through pollen or anther culture [Doré 1977]. In asparagus in vitro culture, the
development of storage roots is essential. Plantlets without well developed storage roots
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