SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/201063
FieldScience the track record for novel species over the last 25 years has been dismal. The typical response most breeders get when they present a brand new species to a salesperson is "But my customers aren't asking for that." I think we will see a handful of novel turfgrasses hit the market in the next decade, but none will gain a sizable market share nor will they be around very long if salespeople do not actively promote them. What do you see as the next major breakthrough? Chandra: The use of major advances in molecular biology, such as genome sequencing. The development of trait-specific molecular markers in marker-assisted breeding will enhance the speed and efficiency of progeny selection and, thus, the cultivar development process. Turfgrasses are genetically complex and are challenging to manipulate since they are perennials and, in most cases, open-pollinated and have higher polyploids. Several new and powerful tools of molecular biology have been developed and are available to us. The adoption of these tools in turfgrass genomics research is in its infancy (unlike major agronomic crops) mainly due to the lack of or limited funding. The turfgrass industry's interest and future funding would significantly enhance our ability to tap into the advances of molecular biology for turfgrass research. Schwartz: Because some mutations happen spontaneously in nature that can lead to herbicide resistance, I think we may see non-genetically modified herbicide resistant turfgrasses. Kenworthy: I think we will see improved drought tolerance and pest tolerance in varieties. This will help to make the turfgrass manager's job easier and make the turfgrass industry more sustainable (by reducing some use of pesticides, for example). Amundsen: We continue to see significant, albeit incremental, gains in overall turf performance. Recent advances, such as rhizomatous tall fescue are interesting, but the major breakthroughs will likely come from host resistance or tolerance to stresses. The quality we have is pretty good and the challenge for most breeders will be developing new varieties that can maintain that quality with fewer inputs. Wipff: There is great need for improved turfgrasses for the renovation and improvement of high use 'park and rec' fields. These characteristics would include faster germ and establishment, significantly improved traffic tolerance and recovery. Brede: For several years now, there have been several vegetatively propagated varieties designed specifically for sod production. We have not seen a similar phenomenon with seeded types, but I believe we are close to seeing some specialized for sod production. Will we see some warm-season grass varieties becoming more cold tolerant? Huang: I am collaborating with Chinese scientists to perform mutation and genetic transformation work to improve cold tolerance in warm-season species. This work is in progress, but we cannot share details at the moment. Chandra: Absolutely. As long as warm-season turfgrass breeders have access to a germplasm source with cold tolerance in the gene pool/germplasm collection, they can work on improving cold tolerance. There is increased interest in the use of warm-season turfgrasses in northern states mainly because of their enhanced wear tolerance and higher water-use efficiency (compared to cool-season turfgrass species). One effort in this direction is a USGA-funded project where Texas A&M AgriLife Research, Kansas State University (Jack Fry and Megan Kennelly) and Purdue University (Aaron Patton) are collaborating on the development of cold-tolerant zoysiagrass cultivars with large patch disease resistance. There are also a few bermudagrasses being tested on golf courses as far north as Pennsylvania. Schwartz: I believe that the breeding programs in Oklahoma and North Carolina will continue working on grasses that can be grown farther north. In Tifton, GA, this is a difficult goal to reach on our own. But, we 36 SportsTurf | November 2013 have established plots in central Illinois and Indiana during the last year that will hopefully allow us to identify warm-season grasses that do well in both northern and southern locations. Amundsen: I think we will continue to see gains in cold tolerance of warm-season grasses and heat tolerance of cool-season grasses, but there are limits to the range of adaptation of most species. As you move away from the zone of adaptation for a species into environments less favorable, some outliers will survive and tolerate a given stress. Since these outliers represent only a small fraction of the diversity for the species, there are genetic limitations to further advancing the species in less desirable regions. The best approach probably lies with inter-generic hybridization to move certain turf traits into more widely adapted species, or move adaptation traits into better performing turf species. This is a challenge because there are limits in compatibility among species which would require a sizeable investment to make significant gains. Fraser: While improvements in cold tolerance or winter survivability are goals for warm-season turfgrass breeders, one objective is to increase the portion of the year that those grasses are green. A warm-season turfgrass may have very good cold tolerance and winter survivability, but that may be because it has long winter dormancy. Cultivars that green up earlier in spring and have good fall color retention, along with winter survivability, will help expand the use of warm-season turfgrasses. Wipff: There are a number of warm-season grasses currently available that are significantly cold tolerant. But, with colder climates typically come longer winters, shorter days, reduced summer temperatures and significantly longer winter dormancy. Prolonged winter dormancy generally precludes warm-season grasses from being used on a widespread basis. Most sod producers already seek out varieties that offer reduced dormancy and early spring green-up. There is some concern that dwarf turfgrass varieties are unable to adequately compete with weeds. What are the pros and cons of dwarf varieties? Fraser:The advantage of dwarf varieties is that their growth habits are very well suited for turf. A very low, very dense growth habit can be beneficial for many uses. Some disadvantages could be that some dwarf plants might have shallower root systems or slower growth rates. Plants with these characteristics might be less tolerant to drought stress, establish more slowly, recover more slowly from injury or be less competitive with weeds. The good news is that there is usually variation in these traits which allows us to select plants that have beneficial characteristics that we can use in the development of new varieties. Chandra: Dwarf varieties are generally slow to grow and spread. Therefore, during the establishment stage, weeds may have a competitive edge. Recovery from damage (mechanical, disease/insect, drought, etc.) in dwarf varieties may be slow, again allowing room for weeds to emerge. Once fully grown-in, however, dwarf varieties are actually better than nondwarf varieties. In addition to reduced mowing requirements, dwarf varieties have superior turfgrass quality, especially in term of higher shoot density that makes it difficult for weeds to creep in. Dwarf varieties retain more leaf tissue below the low mowing height. This is the machinery for photosynthesis and, therefore, dwarf varieties maintain higher carbohydrate reserves, making them stronger than non-dwarf varieties. There is a trade-off between dense, dwarf varieties and their rate of establishment/recovery. Some species respond better to trade-off manipulations than others, and turfgrass breeders work to balance these attributes. Schwartz: Dwarf warm-season grasses (specifically bermudagrasses) are currently the only option for maintaining acceptable golf greens. While less aggressive, I have never seen a non-dwarf Bermudagrass variety make a putting green. In the future, there may be dwarf zoysiagrasses that can be mowed low enough to be planted on golf greens and also have shade tolerance and dense rhizomes that would allow them to grow successfully off of a golf green. www.sportsturfonline.com