“
“The present study was designed to develop a technique for crossing and to gain insight into how sexual reproduction contributes to the maintenance of local populations of Ulva compressa L. To examine the durations of gamete motility and conjugation ability, freshly released gametes were incubated for various periods of time prior to mixing both mating types. The conjugation

ability of the gametes gradually declined after being released from the thalli when the gametes were incubated without mixing www.selleckchem.com/products/BEZ235.html with the opposite mating type. The ability to conjugate decreased by half after 6 h, although most of the gametes remained motile. The gametes released 4 h later had the same level of conjugation ability when mixed immediately after releasing. When the mature thalli were wrapped in a moist paper towel to prevent gametes from being released, the gametes were preservable for Selleckchem GSK1120212 7 h without a significant decrease in their conjugation ability. Conjugation occurred soon after mixing gametes of both mating types and reached a plateau after 30 s. However, conjugation rates did not exceed a rate of ∼70%, even though freshly released gametes were used. Interestingly, a portion of the gametes newly conjugated 30 min after mixing both mating types, and conjugation rates reached a second plateau at ∼90%. Gametes with delayed conjugation

are provided some period of time that allows them to be transported away and increases their chances of mating with more distant also populations, thus contributing to

the maintenance of genetic variation. “
“The green algal genus Ulva includes a speciose group of marine macroalgae inhabiting shallow seas worldwide. Although algal blooms in Asia highlight the opportunistic nature of several “nuisance” species, recent research clearly reveals important positive benefits of Ulva. Applied research requires accurate, reliable, and rapid identification, however, identification of Ulva spp. has met with con-siderable difficulty. Consequently, many have turned to molecular markers to aid in taxonomy. Previous studies of plants and algae have relied heavily on ITS and rbcL. Recently, tufA has been presented as a suitable barcoding gene to facilitate species-level identification of green macroalgae and it is used here to explore the diversity of Ulva spp. in temperate Australia. Ninety Ulva specimens collected from 38 sites across five states were sequenced for this gene region with exemplars from each genetic group also sequenced for rbcL to test for congruence. Collections of Australian Ulva spp. were compared to samples from Asia and North America and exhibited trends consistent with recent studies in terms of species relationships. Results support an overwhelmingly cosmopolitan flora in temperate Australia that contrasts with other Australasian surveys of Ulva that report a greater number of endemics and new species.