Gourieroux Aude M, McCully Margaret E, Holzapfel Bruno P, Scollary Geoffrey R, Rogiers Suzy Y
National Wine and Grape Industry Centre, Wagga Wagga, NSW, Australia; Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia.
Division of Plant Industry, CSIRO, Canberra, Australia; Plant Science Division, Research School of Biology, The Australian National University, Canberra, Australia.
Plant Physiol Biochem. 2016 Nov;108:519-529. doi: 10.1016/j.plaphy.2016.08.016. Epub 2016 Aug 28.
The rachis, the structural framework of the grapevine (Vitis vinifera L.) inflorescence (and subsequent bunch), consists of a main axis and one or more orders of lateral branches with the flower-bearing pedicels at their fine tips. The rachis is crucial both for support, and transport from the shoot. Earlier suggestions that the flowers per se affect normal rachis development are investigated further in this study. Different percentages (0, 25, 50, 75 or 100) of flowers were removed manually one week before anthesis on field-grown vines. Treatment effects on subsequent rachis development (curvature, vitality, anatomy, starch deposit) were assessed. Sections, both fixed and embedded, and fresh hand-cut were observed by fluorescence and bright-field optics after appropriate staining. Emphasis was on measurement of changes in cross-sectional area of secondary xylem and phloem, and on maturation of fibres and periderm. Specific defects in rachis development were dependent on the percent and location of flower removal one week prior to anthesis. The rachises curved inwards where most of the flowers were removed. When fully de-flowered, they became progressively necrotic from the laterals back to the primary axes and from the distal to the proximal end of those axes, with a concurrent disorganisation of their anatomy. A few remaining groups of flowers prevented desiccation and abscission of the rachis axes proximal to the group, but not distally. Flower removal (50%) reduced rachis elongation, while 75% removal reduced xylem and phloem area and delayed phloem fibre and periderm development. 75% flower removal did not affect starch present in the rachis during berry development. Developing flowers affect the growth and vitality of the rachis and the development of its vascular and support structures. The extent of these effects depends on the cultivar and the number and position of flowers remaining after some are removed one week before anthesis.
葡萄（欧亚种葡萄）花序（以及后续果穗）的结构框架——穗轴，由一个主轴和一级或多级侧枝组成，在侧枝的细梢上着生有带花的花梗。穗轴对于支撑以及从新梢进行养分运输都至关重要。本研究进一步探讨了之前有关花朵本身影响穗轴正常发育的观点。在花期前一周，对田间种植的葡萄树人工去除不同比例（0%、25%、50%、75%或100%）的花朵。评估处理对后续穗轴发育（弯曲度、活力、解剖结构、淀粉沉积）的影响。对固定、包埋后的切片以及新鲜手切片在适当染色后通过荧光和明场光学显微镜进行观察。重点在于测量次生木质部和韧皮部横截面积的变化，以及纤维和周皮的成熟情况。穗轴发育的特定缺陷取决于花期前一周去除花朵的比例和位置。在去除大部分花朵的部位，穗轴向内弯曲。当完全去花后，穗轴从侧枝开始逐渐坏死，直至主轴，并从轴的远端向近端发展，同时其解剖结构紊乱。少数残留的花簇可防止其近端穗轴干枯和脱落，但对远端无效。去除50%的花会减少穗轴伸长，而去除75%的花会减少木质部和韧皮部面积，并延迟韧皮部纤维和周皮发育。去除75%的花不影响浆果发育期间穗轴中的淀粉含量。发育中的花朵会影响穗轴的生长和活力及其维管和支撑结构的发育。这些影响的程度取决于品种以及花期前一周去除部分花朵后剩余花朵的数量和位置。
