Monk learns secrets of heredity from pea plants.

BRUNN, Austria, March 1865--It may be the most interesting research on peas since noted Danish science writer Hans Christian Andersen reported that the legume causes insomnia among princesses. An Austrian monk has spent the past decade growing pea hybrids and religiously recording how certain physical traits--pod color, seed shape, and plant height, among others--pass from one generation to the next. He now claims to have found that a few simple rules govern the process.

Johann Gregor Mendel of St. Thomas Monastery, who described his results at this and last month's meetings of the Natural Sciences Society in Brunn, says that physical traits in other plants, as well as animals, may follow similar principles in their inheritance. "I am convinced that it will not be long before the whole world acknowledges the results of my work," he told SCIENCE NEWS.

In his experiments, Mendel examined more than 28,000 pea plants, noting seven traits that each come in two easily distinguishable forms. For example, pods of a pea plant are either green or yellow; their seeds, round or wrinkled; and their height, tall or dwarfed.

To create his hybrids, Mendel brushed the pollen of one pea plant onto the pistils of another. He started by crossbreeding strains that had already proved constant for one form of a trait with strains consistently showing the other form. For example, he crossed a tall strain with one whose stems were always short.

Surprisingly, in light of current hybridization theories, the resulting plants did not show blending of any of the seven physical traits. The crosses between tall and dwarf strains did not produce medium-size plants. Instead, they invariably resulted in tall plants. "Transitional forms were not observed in any experiment," Mendel says.

The monk, who is also a meteorologist, dubs the form of each trait prevailing in the hybrids--green pods, round peas, long stems--"dominant" and the trait that disappears, "recessive." He speculates that through their eggs or pollen, the parents of a hybrid contribute to their offspring an element representing the dominant or recessive trait but not both. Therefore, when pollen and eggs join to form a seed, various combinations of the elements can result, but the presence of a dominant trait will always mask the recessive one.

In further experiments, Mendel allowed his hybrid pea plants to self-pollinate. He discovered that the recessive forms of each trait reappeared in a significant fraction of the offspring, demonstrating that the hybrid somehow continues to carry the recessive element in at least some of its seeds. In one experiment, notes Mendel, hybrids having green pods gave rise to 428 plants with green pods and 152 with yellow ones. Mendel documented similar ratios for all the traits he monitored. He concluded that among the offspring, when two hybrid plants are crossed, the dominant form of a trait generally outnumbers the recessive form 3 to 1.

Moreover, Mendel studied whether choice of one trait, say pod color, influences how often the form of a second trait, such as seed shape, passes from one generation to another. The data clearly indicate that each trait is inherited independently of the other ones, he contends.

Leading botanists contacted by SCIENCE NEWS were either unaware of Mendel's data or openly skeptical about his conclusions. The work on peas is intriguing but "incomplete," says German botanist Carl Wilhelm von Nageli. To confirm its general applicability, von Nageli argues, Mendel should conduct similar hybridization experiments with other plants, such as hawkweed.