但是，传统的杂交育种是一个缓慢的进程。

But traditional crossbreeding is a slow process.

因此要提高它们的含量宜采用杂交育种途径。

Therefore it is suitable to use the process of crossbreeding to increase their contents.

豇豆杂交育种按照传统的方法存在坐果率低的问题。

Cowpea crossbreeding has the problem that fructify cation is low according to the traditional method.

这些杂交育种及基因工程的努力，对于食品科学家和农业学家来说几乎代表了一个新概念。

Such cross-breeding and genetic engineering efforts hardly represent a new concept for food scientists and agriculturalists.