哈氏仿对虾卵巢发育的形态学与组织学观察

根据哈氏仿对虾卵巢的组织学和外部形态特征，卵巢发育可分为六个时期：形成期、小生长期、大生长期前期、大生长期后期、成熟期和恢复期。卵巢发育在浙江海区一年一个周期，产卵期为5月至9月，产卵高峰期在6月至7月，为多次产卵类型。     

Melatonin, but not somatostatin-14 influences in vitro steroidogenesis by ovarian follicles of rainbow trout

Ovarian follicles taken from sexually maturing rainbow trout at the mid-vitellogenic stage of ovarian development were incubated in vitro in the presence or absence of melatonin or somatostatin-14 (SRIF-14) to determine whether there is evidence of a direct action of these factors on gonadal steroidogenesis in fishes. The steroidogenic capacity of the ovarian follicles was assessed by measuring testosterone (T) and 17-estradiol (E₂) release into the incubation medium, and by examining the steroid metabolites produced following incubation of follicles with radiolabelled steroid precursors.Melatonin appears to elicit a biphasic effect on steroidogenesis by in vitro rainbow trout ovarian follicles; at a concentration of 1 × 10^–3 M, melatonin stimulated basal T and E₂ production, but at a concentration of 1 × 10^–2 M there was an inhibition of basal and sGtH-stimulated T and E₂ Melatonin may act to reduce the activity of specific steroidogenic enzymes, since there was evidence of melatonin at 1 × 10^–2 M enhancing the accumulation of [³H]17-hydroxyprogesterone in the medium following incubation with [³H]pregnenolone, possibly suggesting the inhibition of C_17,20-lyase activity. In contrast, SRIF-14, used at concentrations of 1 × 10^–8 M and 1 × 10^–6 M, had no effect on basal or sGtH-stimulated E₂ or T production by ovarian follicles, incubated in vitro.     

Histological Characteristics of the Regression of Corpora Lutea in Wistar Hannover Rats: the Comparisons with Sprague-Dawley Rats

We examined the ovaries of 44 Wistar Hannover (RccHan^TM:WIST) (WH) and 30 Sprague-Dawley (SD) rats at 32-weeks of age to determine whether the ovarian structure and formation/regression of the corpora lutea (CLs) differ between the two strains. The average ovary weight was higher in WH rats. The average number of all CLs, including currently formed and previously formed CLs, was higher in WH rats in all cycles; however, no appreciable difference was detected in the number of newly or currently formed CLs between the two strains. CLs regression characterized by degeneration and necrosis of luteal cells began to appear in diestrus in both strains; however, the distribution of degenerated/necrotic cells in CLs differed. Necrotic cells were scattered in SD rats but were focally observed in the center of the CL in WH rats. The reduction in size of previously formed CLs accompanied by regression started about 2 or more stages later in WH rats than in those of SD rats. In conclusion, the higher number of CLs in WH rats is considered to be due to slow CL regression compared with in SD rats.     

Ascites in a 13‐year‐old miniature horse mare with an ovarian granulosa theca‐cell tumour: A manifestation of Meigs' syndrome?

A 13‐year‐old miniature horse mare presented for evaluation of ascites. Abdominal ultrasound showed severe free peritoneal fluid accumulation as well as a caudal abdominal mass. The peritoneal fluid was characterised as a transudate with no evidence of sepsis. Surgical exploration of the abdomen was performed; copious free peritoneal fluid and a large right ovarian mass were discovered. The abnormal ovary was removed, and the mass was determined histologically to be a benign granulosa theca‐cell tumour. Although there was mild peritoneal fluid accumulation in the immediate post operative period, the ascites effectively resolved with removal of the tumour, and the mare returned to a normal lifestyle. This is similar to reports of Meigs' syndrome in human women, in which a benign ovarian mass of significant size causes ascites that resolves once the mass is removed.     

农杆菌与质粒DNA子房注射法在棉花转基因研究中的应用

为了研究农杆菌和质粒DNA两种子房注射法对普通棉花品种的转化效率,以8891棉花为材料,分别在三亚和常德两地进行了转化试验。结果表明：与质粒DNA注射相比,三亚地区农杆菌注射的转化效率高1.25个百分点;但农杆菌子房注射的落铃率高,获得的种子相对较少;而在不同的地点试验,常德地区的落铃率显著高于三亚地区;而质粒DNA直接注射的成铃率更高,虽然转化率相对较低,但也能获得有效的转化植株。     

Haploidy in tomato (Lycopersicon esculentum Mill.): a critical review

Results on the induction of haploidy in tomato via both gynogenesis and microspore embryogenesis in vitro are far from satisfactory. The number of reports available on the gynogenic induction via in vitro non-fertilized ovary culture, wide hybridization and the use of irradiated pollen are limited. The main reason for this may be the difficulty experienced in working with this species. Therefore, many failed attempts have not been reported. Non-fertilized ovary culture and wide hybridization using Solanum sisymbriifolium Lam. as the male parent seem to be promising (Bal and Abak, Pak J Biol Sci 6:745–749, 2003a, b). Further efforts in this line may improve results obtained earlier. Several reports (Gresshoff and Doy, Planta 107:161–170, 1972; Sharp et al., Planta 104:357–361, 1972; Zamir et al., Plant Sci Lett 17:353–361, 1980; Chlyah and Taarji, Proc. Int. Symp. Plant tissue and cell culture application to crop improvement. 24–29 Sept. 1984; Jaramillo and Summers, J Amer Soc Hort Sci 115:1047–1050, 1990, HortScience 26:915–916, 1991; Summers et al., HortScience 27:838–840, 1992) are available on anther culture of tomato but a working protocol is yet to be developed. For the induction of anther callus, anthers carrying microspores at the meiotic stages appear to be the most responsive. However, the callus and the regenerants obtained were mainly of somatic origin. Somatic tissues of tomato anthers carrying the meiotic stages are highly responsive to tissue culture manipulations in comparison to anther tissues of the later stages. Therefore, reports on the induction of callus from anthers carrying early microspore stages should be met with caution. If culturing young anthers is of any help then it may be that the anther tissues are nursing the microspores and bringing them to the responsive uninucleate stage. Following the first report by Sharp et al. (Planta 104:357–361, 1972) on the induction of microspore embryogenesis, using a modified version of the microspore culture, reports concentrated only on anther culture (reviewed by Chlyah et al., Haploids in crop improvement I. Biotechnology in agriculture and forestry 12. Springer-Verlag, Berlin, 1990). Based on findings reported by Yinnan et al. (J Agric Biotechnol, , 1999) and Bal and Abak (Biotechnol Biotechnol Equip 19:35–42, 2005) on the induction of symmetrical division of microspore nuclei from uninucleate microspores, the formation of multicellular structures and globular embryos, it is likely that the future of tomato haploidy lies in the technique of isolated microspore culture.     

Interspecific hybridization between Cyclamen persicum Mill, and C. purpurascens Mill.

In order to introduce valuable traits from wild species of Cyclamen into C. persicum cultivars, crosses were made between C. persicum‘Reinweiß’and C. purpurascens. Crossing barriers between C. persicum‘Reinweiß’and C. purpurascens were due to late-acting incompatibility reactions. Interspecific hybrids were obtained by using ovary culture. The highest number of embryos was achieved from placentas excised 21 days and 35 days after pollination and transferred to Murashige-Skoog (M.S.)–medium containing 6% sucrose and 1% agar. The hybrids showed a habit and a chromosome number intermediate between the parents. The fragrant flowers were pale red-purple. The chromosome number in root tips was determined as 2n= 41 while in C. persicum it is 2n= 48 and in C. purpurascens 2n= 34. Due to the different parental chromosome sizes, chromosomes of distinct size were still observed in the hybrid. Pollen viability varied between 0.3 and 34.0%. Parents and interspecific hybrids also showed differences in the DNA content of leaf tissue. Flow cytometric analyses were useful in the early identification of hybrids.     

Pre- and post-fertilization barriers to backcrossing the interspecific hybrid between Allium fistulosum L. and A. cepa L. with A. cepa

Summary To facilitate the introgression of desirable traits of Allium fistulosum into the genome of A. cepa, several accessions of the hybrid between these species were pollinated with A. cepa as the recurrent parent, and in vitro ovary and ovule culture were performed to obtain an increase in the recovery of backcross progeny. Compared to the results obtained from seed development in planta, the increase in the number of backcross progeny was generally very limited, and in some cases even a decrease was found. Raising the sucrose concentration in the ovary culture medium resulted in a higher frequency of ovules developing back seed coats but this was not followed by an increase in the number of backcross progeny obtained. Pollen tube growth of A. cepa was disturbed in the styles of the interspecific hybrids. Per ovule, frequencies of micropylar penetration exceeded frequencies of backcross progeny only to a limited extent. Hence, it was concluded that in the tested interspecific hybrid accessions the attainable gain in viable backcross progeny by the application of in vitro culture techniques is limited by strong pre-fertilization barriers acting at the level of stylar incongruity.     

Inheritance of resistance to the papaya ringspot virus-watermelon strain from two different accessions of winter squash Cucurbita maxima Duch.

Researchers have conclusively shown that Sinapis alba (commonly known as yellow mustard) has many agronomic traits which would be beneficial if transferred to rapeseed ( Brassica napus L.). S. alba is resistant or tolerant to all major insect pests of Brassica crops in the Pacific Northwest region of the United States of America. It is also tolerant of high temperatures and drought stress, is shatter resistant and capable of high seed yield without the need for insecticides and herbicides. However, S. alba is considerably lower in oil content and lacks the high oil quality and seed meal quality of rapeseed (i.e. canola). This paper describes a combination of ovary culture and embryo rescue techniques used to develop fertile hybrid plants from the intergeneric cross between S. alba and B. napus . The hybrids were intermediate between both parents for presence of trichomes, leaf shape and color, seed size, pod shape, and seed oil content; showing expression of traits from both parental species. Hybrid plant tissue and seed contained all types of glucosinolate that exists in either B. napus or S. alba, at the same or higher level to the parental species. These hybrid crosses offer the potential for combining the desirable oil and glucosinolate qualities of B. napus with insect and disease resistance characters of S. alba.     

Development of diploid and triploid interspecific hybrids between Lilium longiflorum and L. concolor by ovary slice culture

Ovary slice culture, after cut-style pollination, was used to develop interspecific hybrids between Lilium longiflorum and L. concolor. Reciprocal crosses between diploid cultivars (2n = 2x = 24) were carried out. On the days 30, 35, 40 and 45th after pollination (DAP), ovaries were sliced and cultured on a modified hormone-free Murashige-Skoog (M–S) medium without NH4NO3, supplemented with 6% sucrose, 50 mg/1 yeast extract and 0.25% gelrite at pH 6.3. For the L. longiflorum × L. concolor cross, ovule germination was found to be best at 30 DAP. After transfer to a M–S (half-strength) medium supplemented with 1.5% sucrose and 0.25% gelrite at pH 5.8, diploid and triploid hybrid plants were established. In contrast, ovules from the L. concolor × L. longiflorum cross did not germinate. The hybridity of the plantlets obtained was verified by karyotype and isozyme analysis. The importance of the ovary slice culture technique as a tool to develop new hybrids between incompatible lilly plants is discussed.