Ovary wall

The development of the kernel following fertilization takes 40-50 days and is accompanied by a 1400-fold increase in the volume of the embryo sac the growth of the embryo and accumulation of food reserves in the endosperm is completed by about day 40. A mature kernel has three parts pericarp, endosperm, and embryo (Fig. 1). The pericarp, the tough, transparent, outer layer of the kernel, is derived from the ovary wall and is, therefore, genetically identical to the maternal parent the endosperm and embryo represent the next generation. 

Fruits may also be classified into a number of structural types. The individual seed-bearing structures of the flower called carpels constitute the gynoecium. The seed-containing cavity of a carpel is called the ovary, and its wall develops into the pericarp of the fruit. The edible fleshy part of a fruit most commonly develops from the ovary wall, but it may be also derived from the enlarged tip of stem from which floral organs arise, and sometimes leaf-like structures protecting the flowers may also become fleshy, e.g., in pineapple. 

Wc have tabulated the r( sults of all surface and depression ti sts for pollen tube chemotropism that were made using gynoecia or gyiioccial parts, i.c., stigma, style, ovary wall, ovules. The restriction oii the ba.sis of iiK tliod excludes only the viTy rarly work of Van Tieghem (1809) and. Strasburgor (1878), both of whom worked with solutions rather than solidified media. They came to opposite conc,lu,sions. 

Fig 9.5 Flower morphology of Heterocentron elegans (A)-(B), Clidemia octona (C)-(F) and of Dissotis rotundifolia (G)-(ff). (A) Mature flower bud with four petals (removed) and eight stamens. (B) Detail of flower showing a style surrounded by an extension of the ovary wall at the base. The anthers are provided with basal auriculate appendages. (C) Development of sepal lobes surrounding petal primordia. (D) Initiation of stamens and carpels. Note the... 

Dissotis rotundifolia is pentamerous and diplostemonous (Fig 9.5G). Its stamens are biauriculate with the outer whorl stamens shorter than the inner whorl stamens, which extend almost to the base of the superior ovary (Fig 9.5H). The upper part of the ovary wall, which surrounds the style base is covered in long hairs (Fig9.5H). 

The nuts of chestnut are borne in a spiny wrapper (involucrum), the burr. The fruits of the chestnut are, in botanical terms, nuts, the shell of which is developed from the ovary wall. The edible kernel of the nut is the embryo, mostly consisting of the huge cotyledons, the small root and the embryonic shoot. The embryo is enclosed into a sometimes felty membrane, the pellicle, which develops from the integuments. 

Fig. 5.4. Increase in thickness of ovary wall of sour cherry, from pre-bloom to fruit ripening, showing amount due to increase in number of cells and amount due to enlargement of cells already present. Slanting lines size changes due to cell enlargement. Stippling size changes due to cell division. (After Tukey and Young 1939)...

Firstly, let us consider the source(s) of the reserves laid down in these seeds. The pea pod (formed from the ovary wall) first increases in length and width, and then in wall thickness, attaining maximum fresh weight before the seeds contained therein commence their deposition of storage reserves [58]. It... 

It does seem more likely that the gibberellins synthesized in developing seeds are much concerned with both seed and fruit growth. Work on P. sativum has demonstrated a fairly close relationship between the presence of high gibberellin levels in the seeds and the increases in both absolute and relative growth rates of seeds and ovary wall (i.e. the pod) (see Fig. 3.34). A similar picture has emerged for several other species [126]. 

Fig. 3.34, Ovary wall growth and hormone content of seeds during early seed development...

Pericarp The cereal fruit coat that is formed from the ovary wall. It is divided into three layers exocarp, mesocarp, and endocarp. 

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