A comparison of conventional glassine pollination bags and recently-developed terylene isolation bags for artificial hybridisation of perennial ryegrass (Lolium perenne) is reported.
The yield of seed from plants crossed in a glasshouse using glassine bags was low. When terylene bags were used in the glasshouse, for an identical set of crosses, the seed yield was increased five-fold, while with terylene bags used in the open there was a seven-fold increase. In addition, the seed produced in terylene bags was of higher quality than that from glassine bags. The normal practice of removing the flag leaf laminae of the enclosed culms appeared to be largely ineffective in improving the yield or quality of the seed produced.
From a comparison of the floral environment within a glassine and a terylene bag being used for artificial hybridisation in the glasshouse, it is concluded that the large difference in seed yield and seed quality between glassine and terylene crossing bags was due to differences in the relative humidity of the air within the bags.
The greatly increased seed yield of crosses isolated by terylene bags compared with conventional glassine bags offers new prospects for grass breeding, in that quantities of seed adequate for the assessment of single-cross progenies under simulated sward conditions can be obtained.