ISSN:
1573-5060
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary A series of experiments was conducted to determine the variations arising between replicate selfing units, to compare self-fertility and cross-fertility in the same environment and to measure the variation in expression of self-fertility by different techniques and in different environments. Variation in self-fertility between selfing units within genotypes was relatively high, representing approximately one-third of the total observed variation in a series of duplicate selfings of over 60 genotypes tested in one environment. In order to differentiate clearly between the self-fertility of a limited number of genotypes as many as four replicates were needed, although this number varied with the environment in which the tests were conducted. Levels of self-fertility were similar in bag selfing units placed inside or outside a glasshouse in an average year, but were greater outside than inside in a year which was drier and warmer than average. In a highly humid environment the mean level of self-fertility attained was reduced by a factor of three. Removal of flag leaf laminae had an adverse effect on self-fertility, reducing it by half. Shaking the pollination bags, as is the usual practice to promote pollen dispersal, increased self-fertility very considerably over that of unshaken controls. Assisting pollen dispersal by blowing filtered air into the bags was time-consuming and did not prove to be superior to the shaking technique. It is clear that self-fertility can neither be considered in isolation from the environment in which it is determined, nor can it justifiably be related to cross-fertility unless both are determined in the same environment. A sample of over 60 genotypes tested in one environment was on average 2.2% as self-fertile as they were cross-fertile, with a range for individual genotypes from 0–31%. Optimum conditions for maximum expression of self-fertility, essential in the exploitation of this character in ryegrass breeding, have yet to be fully established.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01904667
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