Name_________________________ HS301- Exam 3-2014 1. (6) Please indicate for each tissue below whether it is classified as "bark" or "wood" in grafting terminology. vascular cambium _____BARK_________________ periderm _______BARK_______________________ pith ____________WOOD______________________ secondary xylem ______WOOD_________________ secondary phloem ____BARK__________________ cortex__________WOOD______________________ 2. (8) Provide an explanation for this micropropagation scenario. Two different micropropagation labs are propagating plants of the periclinal chimeric hosta cultivar 'Sundown'. 'Sundown' has a leaf with a yellow margin and a green center. Plants produced in micropropagation lab 1 are true to type, showing the exact same phenotype (appearance) as the original parent. However, plants produced in micropropagation lab 2 are variable; some plants are identical to the original 'Sundown', but both solid green and solid yellow plants are also recovered in significant numbers. Discounting mutational events, can you explain: A. what may differ in the media being used in these 2 labs? LIKELY THE AMOUNT OF CYTOKININ VARIES BETWEN THE 2 LABS. LAB 2 IS PROBABLY USING HIGHER LEVELS OF CYTOKININ IN THE STAGE 2 PROPAGATION MEDIA B. how does the difference in media formulation relate to the observed differences in the characteristics of the plants coming from the 2 labs? HIGHER LEVELS OF CYTOKININ ENCOURAGE THE FORMATION OF MORE ADVENTITIOUS SHOOTS, WHICH DO NOT ALLOW FOR FAITHFUL PERPETUATION OF A PERICLINAL CHIMERA. PLANTS DERIVED FROM ADVENTITIOUS SHOOTS WILL DEMONSTRATE EITHER OF THE COMPONENT COLORS OF THE CHIMERA, BUT RARELY BOTH. 4. (6) Dwarf fruit trees can be created by three (3) different ways in the nursery industry. List these 3 mechanisms (think about the image of the tall guy in the sunglasses for the 3rd mechanism that you may be challenged to recall). DWARFING ROOTSTOCK DWARFING INTERSTEM GENETIC DWARF SCION 5. (4) Name the two types of grafting techniques that are referred to as "budding". _____CHIP____________ and ______T_______________ 6. (3) Grafting a tree peony scion onto a herbaceous peony root piece is referred to as what type of graft? ___NURSE ROOT GRAFT________________7. (4) Name 2 of the 3 species by common name (1 point extra credit if you can provide the scientific name of both) that occasionally show intraspecific graft incompatibility. ___CORNUS FLORIDA _____ and _____CERCIS CANADENSIS___ALSO ACER RUBRUM__ 8. (3) The hood that one works at when conducting micropropagation procedures, and that provides a sterile working environment, is called a ____LAMINAR FLOW HOOD_________________________ 9. (3) Please name the plant hormone group (or lack of a plant hormone) for each of the following stages of micropropagation. stage 2___CYTOKININ________________ stage 1___NONE________________ stage 3 ____AUXIN_______________ stage 4 ___NONE________________ 10. (4) In our woody plant grafting lab, we conducted both an intraspecific graft combination, and an interspecific graft combination. Can you recall what plant (common name ok) was used in the intraspecific graft combination? __GINKGO________________________. Now, can you recall the rootstock name and the scion name of the interspecific graft combination? rootstock = __PRUNUS CERASIFERA______. scion = ___PRUNUS MUME_______. 11. (6) We discussed the marketing of "HollyPops" by a nursery in NC. A. Can you recall the common names of the scion and the rootstock in the "HollyPop" combinations? SCION = ENGLISH HOLLY (ILEX AQUIFOLIUM). ROOTSTOCK = 'NELLIE STEVENS'. B. Name 2 (two) specific reasons that grafting is utilized to create "HollyPops", rather than simply using rooted cuttings of the scion. PLANTS DEMONSTRATE THE WEEPING ARCHITECTURE OR VARIEGATED FOLIAGE MORE PROMINENTLY. THE ROOTSTCOK CONFERS TOLERANCE TO OUR HEAVY, WET SOILS FOUND IN NC. 12. (3) To date, has a successful graft union been accomplished between grafting partners representing 2 different plant families. Circle YES or NO. NO! 13. (3) What was the name of the rootstock we used for our grafting experiment in which we used Hedera helix as the scion? _____X FATSHEDERA______________ 14. (3) The network of specialized structures that connect the cytoplasm of contiguous cells and whose development is critical to successful graft union formation ______PLASMODESMATA________________________________.15. (3) + Laburnocytisis is a novelty plant we discussed briefly in class that is an example of a ______GRAFT CHIMERA___________________________ 16. (4) Two researchers from the University of Wisconsin discovered the hormonal control of shoot and root regeneration from in vitro callus cultures. Their names are "immortalized" in the names of many micropropagation media used today. Their names are __MURASHIGE_____________ and ___SKOOG_______________. 17. (4) What are the 2 secondary vascular tissues produced by the vascular cambium ___2ND XYLEM___________________ and ____2ND PHLOEM__________________ 18. (3) In an NCSU Horticultural Science plant breeding research program, sweet potato is often grafted onto this rootstock in order to induce flowering in the scion. You did this graft in lab. What is the rootstock name? __BRAZILIAN MORNING GLORY ________ 19. (4) What is unique about the stomata and leaf cuticle of plants propagated in a micropropagation (in vitro) environment? LEAF STOMATA ARE NON-FUNCTIONAL (STUCK OPEN), AND CUTICLE DEVELOPMENT IS LIMITED IN VITRO. 20. (3) Dwarfing rootstocks of apple often induce scions grafted onto them to flower at an earlier age as compared to non-dwarfing rootstocks. We thus say that dwarfing rootstocks induce ______PRECOCITY_______________________. 21. (3) What Christmas tree species important to NC is being grafted onto Abies firma (momi fir) in order to increase its adaptation to NC? ___ABIES FRASERI (FRASER FIR)__. NOTE SPELLING OF FRASER!!!!!!!!!!!!!!________. 22. (3) If you are growing a marginally cold-hardy, heirloom rose cultivar here in Wake County, would it be preferable to have it growing on