Search results
Results from the WOW.Com Content Network
The ability to produce seedless fruit when pollination is unsuccessful may be an advantage to a plant because it provides food for the plant's seed dispersers. Without a fruit crop, the seed dispersing animals may starve or migrate. In some plants, pollination or another stimulation is required for parthenocarpy, termed stimulative parthenocarpy.
In male sterile plants, the parthenocarpy expresses itself only sporadically on the plant with deformed fruits. It has been reported that plant hormones provided by the ovary seed (such as auxins and gibberellins) promote fruit set and growth to produce seedless fruits. Initially, without seeds in the fruit, vegetative propagation was essential.
Parthenogenesis (/ ˌ p ɑːr θ ɪ n oʊ ˈ dʒ ɛ n ɪ s ɪ s,-θ ɪ n ə-/; [1] [2] from the Greek παρθένος, parthénos, 'virgin' + γένεσις, génesis, 'creation' [3]) is a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization.
In stenospermocarpic fruits, normal pollination and fertilization are still required to ensure that the fruit 'sets', i.e. continues to develop on the plant; however subsequent abortion of the embryo that began growing following fertilization leads to a near seedless condition. The remains of the undeveloped seed are visible in the fruit. [1]
In some species, seedlessness is the result of parthenocarpy, where fruits set without fertilization. Parthenocarpic fruit-set may (or may not) require pollination, but most seedless citrus fruits require a stimulus from pollination to produce fruit. [29]
For example, the ‘Valencia’ orange undergoes nucellar embryony in both fertilized and unfertilized conditions. [3] But, it has been found that nucellar embryo development, under fertilized or unfertilized conditions, can take place in different positions.
Other staple food crops, like bananas and plantains, are propagated from cuttings, and produce fruit without pollination (parthenocarpy). Further, foods such as root vegetables and leafy vegetables will produce a useful food crop without pollination, though pollination may be required for the purpose of seed production or breeding.
In contrast to parthenocarpy, which involves seedless fruit formation without fertilization, apomictic fruits have viable seeds containing a proper embryo, with asexual origin. In flowering plants, the term "apomixis" is used in a restricted sense to mean agamospermy, i.e. clonal reproduction through seeds.