Collins noted, among others, these unusual traits of the Chinese maize:
Several unique structural features that enabled the plants to resist the drying out of the silks by wind at the time of flowering
Unusual growth behaviour in that the top four or five leaves all appeared on the same side of the main stem of the plant. Extremely erect leaves of the upper nodes, while the lower leaves were more spread and drooping
One of the main things he noted was the composition of the endosperm of the maize kernels. He wrote: “The texture of the endosperm is one of the unique features of this maize. Cut in any direction it separates with a sort of cleavage, exposing a dull, smooth surface. The texture suggests that of the hardest waxes, though it is still harder and more crystalline. From this optical resemblance to wax the term cereous or waxy endosperm is suggested.” The moisture content of the kernel must be 16% or lower before the waxy trait can be recognised visually.[21]
The starch of normal dent maize is characterised by a content of about 25% amylose with the remainder being amylopectin and the intermediate fraction (see 3.5 Biochemistry). But these percentages vary among cultivars and with kernel development. For example, amylose percentage ranged from 20 to 36% for 399 cultivars of normal maize.[22][23] There are maize germplasm collected that range from less than 20 to 100% complement of amylopectin.[21] And waxy maize contains 100% amylopectin.[12]
Waxy starch is of main interest because fractionation of normal starch to obtain pure amylose or amylopectin is very costly.
Waxy endosperm is inherently a defect in metabolism, and its low frequency in most maize populations in the face of recurring mutations indicates that it is acted against by natural selection.[5]
Collins noted, among others, these unusual traits of the Chinese maize:Several unique structural features that enabled the plants to resist the drying out of the silks by wind at the time of floweringUnusual growth behaviour in that the top four or five leaves all appeared on the same side of the main stem of the plant. Extremely erect leaves of the upper nodes, while the lower leaves were more spread and droopingOne of the main things he noted was the composition of the endosperm of the maize kernels. He wrote: “The texture of the endosperm is one of the unique features of this maize. Cut in any direction it separates with a sort of cleavage, exposing a dull, smooth surface. The texture suggests that of the hardest waxes, though it is still harder and more crystalline. From this optical resemblance to wax the term cereous or waxy endosperm is suggested.” The moisture content of the kernel must be 16% or lower before the waxy trait can be recognised visually.[21]The starch of normal dent maize is characterised by a content of about 25% amylose with the remainder being amylopectin and the intermediate fraction (see 3.5 Biochemistry). But these percentages vary among cultivars and with kernel development. For example, amylose percentage ranged from 20 to 36% for 399 cultivars of normal maize.[22][23] There are maize germplasm collected that range from less than 20 to 100% complement of amylopectin.[21] And waxy maize contains 100% amylopectin.[12]
Waxy starch is of main interest because fractionation of normal starch to obtain pure amylose or amylopectin is very costly.
Waxy endosperm is inherently a defect in metabolism, and its low frequency in most maize populations in the face of recurring mutations indicates that it is acted against by natural selection.[5]
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