‘ a - 1 ’ was selected from a breeding population of forty zoysia matrella plants derived from open - pollinated seed collected from various parts of southeast asia ( japan , philippines , china , korea , vietnam and thailand ). the original plants were vegetatively propagated and evaluated first in pots at sheldon , qld ( australia ). vegetative propagation was performed by using stolons from the original plant and dividing them into stolon tip and single - node cuttings . these cuttings were placed into soilless peat - vermiculite potting mix in nursery cell trays to produce roots and grow through the potting medium before transplanting into larger pots . a shortlist of selected genotypes was expanded to field plantings at sheldon , qld ( australia ). the plants were vegetatively propagated in nursery cell trays prior to planting in the field . once in the field , the plants were evaluated against existing z . matrella and z . matrella × z . japonica hybrid cultivars under mowing heights from 10 to 25mm and under shade levels ranging from 0 to 80 %. ‘ a - 1 ’ from seed collected in northern okinawa ( japan ) showed higher tiller density and a more prostrate growth habit than the parent ecotypes which formed a more open sward and were more erect in their growth habit . ‘ a - 1 ’ was selected from the wider breeding population on the basis of its superior turf colour , quality under mowing for 6 years , and its shade tolerance as shown by its ability to maintain density of the mown sward under greatly reduced light levels ( 70 - 80 % shade ). additional observations regarding climatic adaptation were made in cairns , qld ( australia ) and melbourne , vic ( australia ) using vegetative propagules as described above . ‘ a - 1 ’ has remained true - to - type with no discernible off - types through more than four cycles of vegetative multiplication . ‘ a - 1 ’ is a perennial diploid ( 2n = 40 chromosomes ) zoysia matrella ( l ) merr . zoysiagrass with a creeping growth habit forming a tight mat of stolons rooting adventitiously on the ground surface . it spreads laterally by stolons and rhizomes , which produce very short vertical tillers (& lt ; 10 cm tall ) with fine stems (& lt ; 0 . 6 mm diameter ). the stolons of ‘ a - 1 ’ consist of short , thin internodes separated by compound nodes , each of which is subtended by 3 leaves ( fig2 ). structurally , each compound node consists of two compressed internodes and one normal internode and so can produce axillary stolon shoots ( i . e ., branches ) from any or all of the three component nodes , starting from the component node furthest from the stolon tip and subtended by the outermost stolon leaf ( fig2 ). internodes on ‘ a - 1 ’ are longer than on ‘ diamond ’, but comparable in length to those of ‘ cavalier ’, ‘ zorro ’ and ‘ royal ’. ‘ a - 1 ’ produces fewer early stolon shoots per node than ‘ diamond ’, ‘ cavalier ’ and ‘ zorro ’. stolon color is reddish - purple ( rhs n79a — rhs colour chart , 2001 edition ) when exposed to sunlight . stolon leaf blades are linear - triangular in shape and greatly reduced ( vestigal ) compared with tiller leaves . stolon leaf blades on ‘ a - 1 ’ are longer and wider ( i . e ., better developed ) than those of ‘ cavalier ’ ‘ zorro ’, ‘ royal ’ and ‘ diamond ’. measurements relating to ‘ a - 1 ’ internodes and stolons are described in table 1 and as follows : mean length of 4 th internode from stolon tip .— 23 . 04 mm . mean diameter of 4 th internode from stolon tip .— 1 . 37 mm . mean length : diameter ratio of 4th internode from stolon tip .— 16 . 76 . mean number of axillary shoots at 4th visible stolon node .— 2 . 30 . mean length of outermost leaf sheath on 4th visible node from stolon tip .— 9 . 61 mm . mean length of innermost leaf sheath on 4th visible node from stolon tip .— 20 . 05 mm . mean length of leaf blades on 4th visible node from stolon tip .— 4 . 23 mm . mean width of leaf blades on 4th visible node from stolon tip .— 0 . 85 mm . mean length : width ratio of leaf blades on 4th visible node from stolon tip .— 5 . 04 . tiller length ( i . e ., vertical extension ) on ‘ a - 1 ’ is shorter than ‘ cavalier ’ and ‘ zorro ’, but longer than ‘ diamond ’. leaf blades are rolled in the bud and later emerge to become flat and stiff , linear - triangular in shape with smooth margins and a sharply acute apex . ‘ a - 1 ’ produces shorter , narrower leaf blades than ‘ cavalier ’ and ‘ zorro ’. hairs are absent on both the abaxial and adaxial surfaces of the leaf blade and on the leaf sheath . leaf blade color is dark green ( rhs 137a — r . h . s . colour chart , 2001 edition ). the tiller stem and leaf sheath are mid - green ( rhs 138b — r . h . s . colour chart , 2001 edition ). the ciliate ligule consists of a row of short silky white ( rhs n155a — r . h . s . colour chart , 2001 edition ) hairs up to 4 mm long . measurements relating to ‘ a - 1 ’ tillers are described in table 1 and as follows : mean length of flag leaf sheath on flowering tillers .— 22 . 73 mm . mean length of flag leaf blade on flowering tillers .— 3 . 90 mm . mean width of flag leaf blade on flowering tillers .— 0 . 71 mm . mean length : width ratio of flag leaf blade on flowering tillers .— 5 . 49 . mean length of sheath on fourth leaf on flowering tillers .— 10 . 22 mm . mean length of blade on fourth leaf on flowering tillers .— 17 . 98 mm . mean width of blade on fourth leaf on flowering tillers .— 1 . 61 mm . mean length : width ratio of blade on fourth leaf on flowering tillers .— 11 . 12 . ‘ a - 1 ’ flowers from about april to october in the southern hemisphere , and october to april in the northern hemisphere . the inflorescence is a short , terminal , spike - like raceme 12 - 24 mm long , 1 . 2 - 1 . 6 mm in diameter , and dark greyed - orange in colour ( rhs 166a — r . h . s . colour chart , 2001 edition ) while immature . the peduncle below the inflorescence is mid - green ( rhs 138b — r . h . s . colour chart , 2001 edition ) in color . ‘ a - 1 ’ produces longer peduncles and racemes and has more spikelets per inflorescence than ‘ cavalier ’, ‘ zorro ’, ‘ royal ’, and ‘ diamond ’; the density of spikelets on the raceme ( number per mm of length ) is also significantly higher than for ‘ cavalier ’, ‘ zorro ’, ‘ royal ’ and ‘ diamond ’. peduncles on ‘ a - 1 ’ are thinner than those on ‘ cavalier ’, ‘ zorro ’, and ‘ royal ’, but thicker than ‘ diamond ’ peduncles . mature spikelets are glabrous , pale greyed - yellow in colour ( rhs 161c — r . h . s . colour chart , 2001 edition ), narrowly ovoid ( 2 . 5 - 3 . 0 mm long x 0 . 8 - 1 . 0 mm wide ) in shape with the upper glume tapering to an acute apex minutely bilobed and tipped with a short mucronate awn to c . 1 . 0 mm long . measurements relating to ‘ a - 1 ’ peduncles , racemes , and spikelets are described in table 1 and as follows : mean length of peduncle .— 41 . 54 mm . mean width of peduncle .— 0 . 56 mm . mean raceme length .— 17 . 94 mm . mean number of spikelets per inflorescence .— 23 . 5 . mean number of spikelets per mm of raceme length .— 1 . 31 . ‘ a - 1 ’ was compared against other zoysia matrella and z . matrella × z . japonica cultivars ‘ diamond ’, ‘ cavalier ’, ‘ royal ’, and ‘ zorro ’ in a spaced - plant field trial at cleveland , qld ( australia ) ( latitude 27 ° 32 ′ s , 153 ° 15 ′ e , elevation c . 50 masl ). morphological grouping characteristics used to select the most similar comparator varieties of common knowledge were stolon internode length , leaf blade length and width , leaf length and width on flowering tillers , peduncle length and width , and inflorescence length ( table 1 ). rooted vegetative plugs 5 cm in diameter were taken from nursery stock and planted on a basaltic red ferrosol soil on march 3 , 2003 on a 1m × 1m grid . thirty spaced plants from each of the five cultivars were arranged in three randomized blocks with ten plants per plot . weed control was achieved by a pre - emergence application of oxadiazon ( repeated on jul . 23 , 2003 ) and with post - emergence fluroxypyr for broadleaf weeds on mar . 23 , 2003 . good nutrition was maintained by regular applications of slow release complete npk fertilizer at one - to two - month intervals . the spaced plants were allowed to grow and develop without any mowing . leaf and stolon colors were determined on jul . 16 , 2003 . diameter of spread was taken from four measurements per plant made on aug . 22 , 2003 . shoot and inflorescence characteristics were measured on two mature tillers between september 17 and 19 , 2003 . stolon stem and leaf characteristics were measured on two stolons per plant between oct . 6 and 10 , 2003 . digital images of stolon characteristics ( fig1 ) were taken dec . 10 , 2003 . ‘ a - 1 ’ shows excellent salt tolerance . in a greenhouse experiment , six salinity levels covering the range from 60 to 25 , 600 ppm total dissolved salts ( tds ) applied as nac1 were imposed hydroponically through the irrigation water . after being held at the designated treatment levels for thirteen weeks , the level of leaf firing induced in ‘ a - 1 ’ was comparable to that in ‘ diamond ’, ‘ cavalier ’, ‘ zorro ’, and ‘ royal ’ ( table 2 ). the relative dry matter yield of clippings over the ten - to fourteen - week period in ‘ a - 1 ’ was lower than ‘ diamond ’ and ‘ royal ’ at the highest salinity level ( 25 , 600 ppm tds ), but was superior to the other four cultivars at 5 , 120 ppm tds and generally comparable to them at intermediate salinity levels ( table 3 ). ‘ a - 1 ’ is tolerant of zoysia rust ( puccinia zoysiae ) and is resistant to rhizoctonia blight . it is also resistant to sod webworm ( herpetogramma licarsisalis ) and armyworm ( pseudaletia spp ., spodoptera spp . ), except where excessive nitrogen fertilizer use causes softer leaves . ‘ a - 1 ’ has shown superior drought and winter hardiness to ‘ diamond ’, ‘ cavalier ’, ‘ zorro ’ and ‘ royal ’ in a trial at south oakleigh , vic ( australia ) ( 37 ° 55 ′ s , 145 ° 06 ′ e ). in plots planted with rooted stolon cuttings in october 2004 , ‘ a - 1 ’ grew in faster and maintained good ground cover and turf quality ( ratings 4 . 0 - 7 . 0 ) over the following two summers relative to the other 4 cultivars . following summer drought without irrigation , turf quality - cover ratings for ‘ diamond ’, ‘ cavalier ’, ‘ zorro ’ and ‘ royal ’ declined to 1 . 5 - 2 . 0 ( compared with 4 . 0 for ‘ a - 1 ’) in march 2006 , and did not recover over the 2006 winter . at the end of the trial in march 2007 ( 2½years after planting ), turf quality - cover ratings for ‘ diamond ’, ‘ cavalier ’, ‘ zorro ’ and ‘ royal ’ remained very low ( 1 . 5 - 2 . 5 ) compared with ‘ a - 1 ’ ( 6 . 0 ). dna was extracted from ground leaf material using a modified ctab ( cetyl tri - methyl ammonium bromide ) procedure . inter - simple - sequence - repeat ( issr ) markers were generated by the polymerase chain reaction ( pcr ) using a geneworks thermal cycler and two fluorescently labelled primers , 6fam ( ag ) 9 c and ned ( ga ) 9 t . amplification products were separated by capillary electrophoresis using an abi 3130 genotyper and visualised using genemapper ® software . the dominant markers generated with both primers were then used to produce a dendrogram ( fig3 ) using pattern analysis . distinctive marker loci were identified by both primers . fig4 , as an example , illustrates the distinctive marker loci identified using primer 6fam ( ag ) 9 c .
an asexually reproduced cultivar of perennial zoysiagrass that possesses a unique combination of characteristics including high turf quality and density under mowing , good shade tolerance , salinity tolerance , resistance to zoysia rust and rhizoctonia blight , moderate to good resistance to tropical sod webworm and armyworm , and a distinctive dna profile .