EXAM I HORT 326 FEBRUARY 15, Indicate the most correct answer in the left hand column (2 pts./question = 34 pts.).

Transcription

1 EXAM I HORT 326 FEBRUARY 15, 2005 Indicate the most correct answer in the left hand column (2 pts./question = 34 pts.) In apomixis the development of the embryo from the megaspore mother cell is characteristic of: a. polyembryony b. adventitious or nucellar embryony recurrent apomixis c. recurrent apomixis In the formation of the eight nuclei (cells) of the embryo sac, how many mitotic divisions occur proceeding meiosis? a. 1 b. 2 c. 3 d. 4 e. 8 A long-day plant has a critical photoperiod of 14 hours. The plant will flower when: a. the photoperiod is less than 14 hours b. the photoperiod is greater than 14 hours c. the photoperiod is equal to 14 hours e. b & c Seed of some plant species rely on the perisperm for storage of food reserves; the perisperm is derived from the following tissue: a. nucellus b. cotyledons c. female gametophytic tissue d. hypocotyls e. endosperm 5. The following propagules need to form both adventitious buds and adventitious roots a. stem cuttings b. leaf bud cuttings c. root cuttings e. b & c 6. The following plant growth regulator would most likely cause senescence of flowers or ripening of fruit such as bananas or pineapples : a. auxin b. ABA c. ethylene d. gibberellic acid e. cytokinin

2 In nonrecurrent apomixis: a. an embryo can develop from the egg cell without fertilization b. an embryo can develop from the microspore mother cell c. fertilization always occurs in the development of the embryo 8. Which two phytohormones share the same chemical pathway and are the most important hormones affecting seed germination: a. ethylene & gibberellic acid (GA) b. auxin & ethylene c. gibberellic acid (GA) & abscisic acid (ABA) d. auxin & cytokinin e. abscisic acid (ABA) & ethylene 9. The major advantage of seed fluid drilling systems is: a. preventing disease b. more efficient seed handling and assurance of uniform seedling stand establishment c. overcoming double dormancy requirements d. overcoming secondary dormancy requirements e. determining % germination 10. With clonal propagation: a. grafting and budding systems are used to speed up maturation of plants b. cultural treatment of stockblocks (motherblocks) can keep plants in a more juvenile condition, which enhances the rooting of cuttings taken from the block c. greater genetic diversity occurs than with sexual (seed) propagation, which can be important for new selections and overall plant resistance to disease and insect pests. 11. What type of seed dormancy most commonly requires a warm-moist stratification requirement? a. internal dormancy b. rudimentary embryo c. physiological shallow dormancy d. thermodormancy e. external dormancy 12. In plants where the phytochrome system controls seed germination: a. red light produces more phytochrome far-red pigment which promotes germination b. darkness has no effect on phytochrome far-red pigment c. far-red light produces more phytochrome red pigment which promotes germination d. red light produces more phytochrome red pigment which promotes germination e. in the absence of light more phytochrome far-red pigment is produced 2

3 13. Orthodox seeds generally have: a. low respiration rates b. low moisture levels c. a short viability d. a, b & c e. a & b Primed or "vigorized" seeds are: a. germinated in vats that utilize sugar gradients to separate out viable chits vs. nonviable seed b. pretreated in salt solutions such as K 2 HPO 4, KNO 3, and NaCl c. planted after their radicle has elongated d. a, b & c e. a & b 15. The following plant growth regulator inhibits α-amylase production, which is important in the digestion of starch in barley: a. abscisic acid (ABA) b. auxin c. ethylene d. cytokinin e. gibberellic acid (GA) 16. With the Speedling System: a. seedlings can be grown under highly automated, mechanized systems b. production costs are higher compared to direct seeding in the field c. bottomless containers are used which allows air-pruning of roots d. a, b & c 17. If a 6N female parent was crossed with a 10N male parent, the ploidy of the zygote, endosperm and nucellus would be respectively: a. 16N, 22N, 8N b. 6N, 22N, 6N c. 14N, 12N, 16N d. 8N, 20N, 8N e. 8N, 11N, 6N 3

4 -4- Circle the most correct answer to the following true-false statements. IF THE ANSWER IS FALSE, EXPLAIN (WRITE) WHY. (2 pt./question = 42 pts.). T F 18. T F 19. During Stage II of seed germination the imbibition of water occurs rapidly, membranes become reorganized, starch is converted to carbohydrates and proteins degraded to amino acids. Pollen grains contain auxin and ACC, which is the precursor to ethylene. T F 20. Tests for measuring seed viability include: X-ray analysis, tetrazolium, and water flotation tests. T F 21. T F 22. T F 23. T F 24. T F 25. T F 26. T F 27. T F 28. The teste is generally a heart-shaped structure produced in a tissue culture system from somatic or vegetative tissue. In seed production, breeders seed provides the initial seed source of all seed classes, while registered seed is produced in the largest volume and sold to growers. The accelerated-aging test is important for evaluating seed vigor, by subjecting seeds to high temperature and high relative humidity, which causes a rapid deterioration of low quality seeds. During mitosis there is reduction division and genetic segregation in the production of gametes. A monoculture occurs when large numbers of clonally propagated plants are produced in mass. All seeds are sexually produced, whereas all explants used for tissue culture production are clones. Seed stratification with warm-moist treatments can be used to overcome external dormancy requirements. Seed priming systems include osmoconditioning and infusion of solvents. T F 29. T F 30. T F 31. T F 32. T F 33. Erratic germination in lettuce seed due to thermodormancy seed can be overcome by seed priming with salts or gibberellic acid. For short-day stock plants to remain vegetative to maximize rooting of stem cuttings, plants are maintained under short-day conditions by using black cloth to exclude light. In epigeous germination the epicotyl rises above the soil surface, while the cotyledons remain below the soil surface. In the dry process of seed collection harvested onion seed and fruit will be placed in a liquid fermentation tank for 24 hours so seeds will be more easily detached from placental tissue; the seeds are subsequently dried down. Seed priming differs from regular seed germination in that digestion and translocation stages are prolonged (prior to drying down the primed seed) and the radical does not emerge. T F 34. A hardwood cutting is normally collected when the stock plant is actively growing, whereas a herbaceous cutting is taken after growth of shoots starts to harden-off and become more lignified during late-spring. 4

5 T F A fruit is a mature ovary containing both an embryo and endosperm. T F 36. Vivipary is the process of seed germinating while still attached to the maternal plant. T F 37. T F 38. single A good seed priming agent will increase or extend the median germination time (MGT) without reducing overall percent seed germination. Spontaneous generation refers to the ability of plants to clonally regenerate themselves from cells. (5 pts.) 39. Name and describe in DETAIL the three stages of seed germination. At which stage does the radicle emerge? (5 pts.) 40. You have collected bulk seed from a highly valuable, woody ornamental shade tree. However the germination of the seed is erratic and you suspect possible double dormancy. 1) What kinds of double dormancy are there, and 2) describe four different types of preconditioning treatments you could use to overcome double dormancy to enhance more uniform seed germination. 5

6 -6- (15 pts.) 40. Match the correct term with its definition. There should be just one term per definition. Not all the terms have matching definitions. Accelerated Aging Auxin Cline Cultivar(s) Damping Off Epigenetic Fertigation Genotype Heterozygous Homozygous Hybrid Vigor Imbibition Land-Grant Orthodox Seeds Phenotype Plug Production Precision Seeder Purity Recalcitrant Seeds RNA polymerase Stratification Thermodormancy Totipotency Vacuum Seeder Antisense RNA Strand Best Management Practices (BMP) Clone Cytokinin DNA Finger Printing Ethylene Fluid Drilling Gibberellic Acid Hilum Horticulture Hybrid Lines Integuments Land-Races Nursery Phase Change Phytochrome Physiological Deep Dormancy Provenance Quiescent (Quiescence) Recombinant DNA Technology Scarification Tetrazolium Thermotherapy Transplant Shock Water Potential 6

7 -7- _ Ecotypic variations that occur continuously between locations of wild populations of plants selected for their seed. _ A plant hormone that controls adventitious root formation and stages of micropropation. _ Fertilizing plants during irrigation with a soluble fertilizer source. _ External, environmental factors that inhibit seed germination. _ The art and science of the production of ornamental, vegetable and fruit crops. _ Developmental cycles of a woody plant as it progresses from a juvenile to a transition to a mature form. _ Allows the production of transgenic plants where a piece of cloned DNA from an organism is inserted into the DNA of another organism to alter its genotype, producing a transgenic plant. The ecotypic origin of seed which is important for plant survival and optimal performance. A system for sowing seed chits in a gel to protect emerged radicles. Death of young seedlings from pathogens such as Pythium, Rhizoctonia and Phytophothra. Used to turn off gene sequences within the chromosome. The percentage by weight of the desired seed present in sample. A secondary dormancy caused by high temperature conditions that can inhibit germination and uniform seedling stand of lettuce Overall appearance and performance of an organism caused by the interaction of its genotype and the environment. When the size and growth of the resulting seedling population exceeds that of the original parental lines. 7