Corn breeding

The North American experience is a model, of corn improvement through a breeding process that was quite successful.

Although early systematic corn breeding began in the United States in the 20th century corn has become an important crop worldwide.

Corn was domesticated by early Central American Indians who, using mass selection methods, developed many cultivate open-pollinated races.

Modern open pollinated varieties have survived hundreds of generation of selection in cultivation, and it is become the best genetic resources for developing inbred lines that enhance performance when hybridized.

A major activity in modern corn breeding is to improve their adaptedness: including maturity duration, response to soil fertility, cold tolerance and resistance to heat and drought.

Another reason is to increase the quality of corn: including high protein content, high oil content and high protein quality.

A large portion of corn breeding effort is devoted to improving established inbreds by backcrossing individual genes for quality or disease resistance.

Backcrossing is a key feature of breeding programs for many crop species. Incorporating single genes for pest resistance, plant architecture, photoperiod response, quality and other traits is a common feature in the breeding of many crops.

By using conventional plant-breeding methods, hybrid performance improvement will continue and probably at an accelerated rate.

Development at additional tools and breeding methods should contribute to even higher yield, standability and stress resistance over time.
Corn breeding

History of Selection and Improvement of Blueberries

History of Selection and Improvement of Blueberries
During the 1890s, various plant scientists in Maine, Michigan, New York, Rhode Island, and other areas made limited efforts to select and transplant particularly good wild bushes for commercial production.

None of these was successful.

Recognizing both the potential widespread commercial value of the blueberry and the demand for the fruit on the Boston market, Dr. Frederick V. Coville, a botanist with the United States Department of Agriculture, began extensive research on the plant in 1906.

He joined forces with the commercial grower who had been instructing her workers to select and transplant especially good will blueberry plants from the wetlands surrounding her bog.

After discovery the plants’ soil requirements, Dr. Coville de devoted another two years to their culture from seed to fruit and investigated methods of propagating and pollinating the bushes.

In 1908, the first wild highbush blueberry plant for breeding purpose was selected in Greenfield, New Hampshire and named ‘Brooks.’

By the time of his death in 1937, Dr. Coville had propagated over 68,000 seedlings, from which he had selected and introduced 15 improved cultivars (some of them third generation hybrids).

Coville and others realized that interspecific crosses could readily be made between species with the same chromosome number (homoploids).

He recorded successful hybrids between Vaccinium stamineum L. (deerberry) and V. myrtilloides Mich. as well as between V. melanocarpum Mohr. and V. myrtilloides Mich.

The discovery of interspecific hybridization permitted plant breeders to combine desirable traits (such as cold hardiness, higher sugar content, and drought tolerance) of several species into a single plant.

Interspecific hybridization ensures the diversification not only of the blueberry industry but also of the gene pool available to growers.

This diversification is nature’s way of guaranteeing that no single natural calamity will obliterate blueberry production.

To extend the range of blueberry production into northern areas, breeders following Dr. Coville’s lead have crossed the highbush with the lowbush species to reduce plant height, thus taking advantage of insulating snow cover, while at the same time increasing fruit size.

Many of the progeny also have flexible canes that bend but do not break, under snow.

The half highs are often twiggy and strongly rhizomatous, and they may spread out of their rows when planted too far south.
History of Selection and Improvement of Blueberries