Floral gradient in flowering tobacco in relation to free amino acids

By employing TCLs (thin cell layers) culture, the floral gradient in flowering tobacco of different developmental stages was confirmed. The TCLs from early flowering tobacco regenerated more floral buds than those from the tobacco plants in full blooming or fruiting stages. Analysis of free amino acid levels revealed the acropetal gradient of Pro in flowering tobacco stem. L-Pro. L-Trp. D,L-Met and L-Arg were respectively added into the culture medium for testing their influence on floral bud formation from tobacco pedicel segments. Only L-Trp evidently enhanced the floral bud neoformation.

Wrinkled petals and stamens 1,is required for the morphogenesis of petals and stamens in Lotus japonicus

Although much progress has been made in understanding how floral organ identity is determined during the floral development, less is known about how floral organ is elaborated in the late floral developmental stages. Here we describe a novel floral mutant, wrinkled petals and stamens1 （wps1）, which shows defects in the development of petals and stamens. Genetic analysis indicates that wpsl mutant is corresponding to a single recessive locus at the long arm of chromosome 3. The early development of floral organs in wpsl mutant is similar to that in wild type, and the malfunction of the mutant commences in late developmental stages, displaying a defect on the appearance of petals and stamens. In the mature flower, petals and stamen filaments in the mutant are wrinkled or folded, and the cellular morphology under L1 layer of petals and stamen filaments is abnormal. It is found that the expression patterns of floral organ identity genes are not affected in wpsl mutants compared with that of wild type, consistent with the unaltered development of all floral organs. Furthermore, the identities of epidermal cells in different type of petals are maintained. The histological analysis shows that in wpsl flowers all petals are irregularly folded, and there are knotted structures in the petals, while the shape and arrangement of inner cells are malformed and unorganized. Based on these results, we propose that Wpsl acts downstream to the class B floral organ identity genes, and functions to modulate the cellular differentiation during the late flower developmental stages.

Effect of Different Growth State of Broccoli (Brassica oleracea var. italica) on Low Temperature Induction

In order to study the responding of different growth state on low temperature in Broccoli (Brassica oleracea var. italica), we took prematurity broccoli hybrid as the objects. It was found that growth state was varied under different sowing time , moreover, stem became wider with the increasing of light density at the same leaf age. Seedling age of responding to low temperature vernalization only when they grew five leaves above and with over 3.03 ±0.07 centimeter stalk width in 'Qingfeng Broccoli 103'. The older leaf age was and the stronger plant was, the more sensitive and the shorter demanded duration time on low temperature was, and the shorter time required when the plants entered into critical period of floral bud differentiation.

Flower Development and Anatomy of Agapanthus praecox ssp. orientalis (Leighton) Leighton

Floral buds of Agapanthus praecox ssp. orientalis were observed under dissecting and optical microscope to characterize floral organs development and to study relationships between anther development and microsporogenesis. Floral organs differentiation was comprised of 6 distinct stages including nought differentiation, inflorescence bud differentiation, floret primordia differentiation, tepal primordia differentiation, stamen primordia differentiation, and pistil primordia differentiation. Six tepals differentiated almost simultaneously which cross arranged in space and appeared in hexagonal distribution pattern. Six stamens were differentiated inside the tepals at the same time. Finally, 3 carpel primordia differentiated and formed syncarpous pistil. The whole process of floral bud differentiation took approximately 40 d with the first 3 stages developing more slowly than the later 3 stages. Morphology and color of the anther underwent obvious changes during the period between stamen primordia differentiation and anther maturation. Microspores also underwent significant development during this same interval. The relationship between the process of microsporogenesis and anther development has already been made clear by the sauash techniaue.