1. MONOTOCA SCOPARIA TWO FRUITS Betsy R. Jackes James Cook University Peter G. Kevan University of Guelph

2. MONOTOCA SCOPARIA Subfamily Styphelioideae, family Ericaceae Shrubs to 1.3 m tall, lignotuber present Inflorescence axillary, few-flowered spikes often clustered Functionally dioecious or ? Ovary 1-locular Fruit a drupe, yellow to orange

3. OBSERVATION ALL REPRODUCTIVE PLANTS NEAR PALUMA PRODUCED FRUITS. MAIN QUESTION IS MONOTOCA SCOPARIA GYNODIOECIOUS, FUNCTIONALLY DIOECIOUS OR?

4.  Townsville Wet Tropics bioregion Where are we?  BRISBANE Queensland

6. STUDY SITES THREE POPULATIONS ALONG A DECREASING RAINFALL GRADIENT QUADRAT 30 X 18 M ALL PLANTS AT EACH SITE SEXED AND TAGGED AND CO-ORDINATES RECORDED ARE SEXES RANDOMLY DISTRIBUTED OR NOT?

7. Site 1 19 o 00’ 27.8”S 146 o 05’ 31.3”E

8. Distribution Site 1

9. Site 2 19 o 00’ 08.1”S 146 o 04’ 48.7”E

10. Distribution Site 2

11. Site 3 18 o 59’ 59.5”S 146 o 04’ 29.5”E

12. FEMALE PLANTS (WITH STAMINODES) MALE PLANTS (WITH FERTILE STAMENS) WERE RANDOMLY DISTRIBUTED AT ALL SITES DESPITE VARIATIONS IN TOPOGRAPHY AND MOISTURE LEVELS

13. IS THERE A DIFFERENCE IN THE NUMBER OF FLOWERS PRODUCED PER SEX? For each sex, 10 plants tagged, 10 sprigs per plant tagged, each sprig 10 cm long, all flowers counted Femalemean 1381, SD 196 Malemean 1295, SD 240 No significant difference

14. Female sprigsMale sprigs

15. ♀ Male flower, c. 2.1 mm long Female flower c. 1.5 mm long

16. DO MALE AND FEMALE PRODUCE EQUAL QUANTITIES OF NECTAR? Sprigs cut and placed in water, covered with a plastic bag, left overnight Then checked under a dissecting microscope and scored for the amount of nectar present.

17. 1 = brim full 2 = well above ovary but not overtopping the style 3 = visible sparkle at base of corolla tube 4 = no visible nectar

18. NECTAR RESULTS Female n=150Male, n= 192 1 (none visible) 560 2492 33272 4 (brim full) 1396 Female flowers produced significantly more nectar than male flowers

19. POLLEN Pollen from 10 plants, 4 flowers per plant Stained with Alexander’s Stain – grains unstained or partially stained and irregular in shape recorded as aborted. Pollen grains per flower ranged from 2437 to 13375 mean 8762 % fertility or non-aborted grains = 81.9%

20. TWO FRUITS Fruit from female plant firmly attached to parent globular to pear-shaped 2.4-2.7 mm long, 2.1-2.4 mm wide Fruit from male plant weakly attached to parent cylindrical 2.5-3 mm long, 1.25-1.5 mm wide

21. Female plant

22. Female, mature and maturing

23. Male, mature and maturing

24. FRUIT SET All fruit present on the tagged plants were collected after 2 months. Percentage fruit set based on the number of buds and flowers recorded for each plant. Combined data for sites 1 and 2 Female27.11% Male11.41%

25. ‘female’ ‘male’

26. Presence or absence of a well-developed embryo Fruits collected from both sites 1 and 2 Method 1: Fruits cut in half and nature of the embryo noted microscopically, n=20 Method 2: Fruits cleared with methyl salicylate (modified from Stelly et al. and Scriballo & Barrett). All questionable results confirmed by sectioning Method 3: squishing

27. SexSite# examined #well-developed embryos female1154 87 2296142 450229 male13270 22160 (2 partial) 5430 Note: No females without partially developed embryos

28. ‘female’ seeds with endocarp 2.1-2.5 mm long, 1.2-1.5 mm wide

29. FLORAL VISITORS 20 plants, 10 of each sex, 4 sweeps per plant All insects captured and examined for pollen load Only Trigona ?carbonaria carried Monotoca pollen. Male plants, 21 bees captured 10 with pollen, 11 lacking pollen Female plants, 23 bees captured 7 with pollen, 16 lacking pollen

30. CONCLUSIONS Monotoca scoparia is functionally dioecious, sexes are randomly distributed Two fruits develop but no viable embryos in ‘male’ fruit Flowers differ in size and shape with sex Female flowers produce considerably more nectar than male flowers Trigona ? carbonaria is the pollinator