) cell growth on the abaxial side, causing curling. Materials and Methods Plant materials and growth conditions. Seeds of Japanese radish ( Raphanus sativus L. var. longipinnatus ) were purchased from Nakahara Seed Product Co., Ltd. (Fukuoka, Japan). We
rotundus ) density and nitrogen rate on radish ( Raphanus sativus ) yield Weed Sci. 46 661 664 Schueneman, T.J. Sanchez, C.A. 1994 Vegetable production in the EAA, p. 238–277. In: A.B. Bottcher and F.T. Izuno (eds.). Everglades Agricultural Area (EAA
The inheritance of 7 characters in Raphanus sativus L. was studied. Resistant reaction to Albugo Candida race 1, Ac1 , pink pigmentation in plants, Pi, and purple colored pods in R. sativus var. caudatus. Pu, are controlled by single dominant genes, Ac1 and Pi are linked and 3.28 map units apart. Male sterility, ms1 , yellow-green leaves, yg, and cream pollen, cp, are all controlled by separate, single recessive genes. Digenic recessives, gf1gf2 , control green flecking on leaves. No linkage could be detected between Ac1 and ms1 or between ms1 and yg.
There are two evolutionary pathways in the genus of Brassica, one is rapa/oleracea lineage and the other is nigra lineage. Based on the morphological characteristics and nuclear RAPD or RFLP markers, genus Raphanus was thought more closely related to nigra lineage than to rapa/oleracea lineage (Song et al., 1990; Thormann et al., 1994). RFLP data of both chloroplast and mitochondria revealed that Raphanus is more closely related to rapa/oleracea lineage (Palmer and Herbon, 1988; Warwick and Black, 1991; Pradhan et al., 1992). We have previously demonstrated that Raphanus sativus is more closely related to nigra lineage using nuclear intergenic spacer between 5S rDNA and internal transcribed spacer region between 18S and 25S rDNA. In this study, we analyzed DNA sequences from different regions of chloroplast and showed that Raphanus sativus was closely related to rapa/oleracea lineage than to nigra lineage. These results suggest that Raphanus sativus is a hybrid between B. rapa/oleracea and B nigra lineages as proposed by Song et al (1990). The split time between these two lineages and the divergent time of Raphanus was also determined based on these chloroplast DNA sequences.
Previous research indicated that Raphanus sativus L. `Chinese Radish Jumbo Scarlet' (CJRS) has an obligate vernalization requirement for flowering and can be vernalized as an imbibed seed in less than 10 days at 6 °C. For these reasons, it serves as an excellent model system for vernalization studies. This study was initiated to gain an understanding of the interaction between cold duration, exogenously applied GA3, and photoperiod on R. sativus CJRS flowering. R. sativus CJRS seeds were sown in 90-mm petri plates on Whatman no. 1 filter paper saturated with plain water or a solution containing 10-5 M or 10-3 M GA3. After germination (i.e., when the radicle was visible), seedlings were either directly transplanted into 10-cm pots and placed in a greenhouse, or transferred to another petri plate onto filter paper saturated with water only and placed in a growth chamber at 6 °C (75 μmol•m-2•s-1 for 8 h) for 2, 4, 6, 8, or 10 days. Greenhouse conditions were: 20 °C, ambient light (December to January, St. Paul, Minn.) plus 70 μmol•m-2•s-1 supplemental light (high-pressure sodium lamps, 0830-1630 hr), under either an 8-h photoperiod (covered with opaque cloth from 1630-0830 hr), or ambient photoperiod plus night-interruption lighting (2 μmol•m-2•s-1, using incandescent lamps, 2200-0200 HR). Results will be presented.
Self-incompatibility of Raphanus sativus L. was partially overcome by exposing plants to temperature of 30 to 50°C. The most effective treatment was 50°C for 25 minutes. Scanning electron microscopical (SEM) observation of pollen tubes on the papillae surface have shown that exposure of the gynoecium to 50°C for 25 minutes resulted in pollen tube growth following self-pollination that resembled that of cross-pollination. Openings of papillae and detached pollen grains and tubes were found as the result of successful pollen tube penetration of papillae. Fluorescence microscopical (FM) observation served to confirm these observations made by SEM. However, incompatible pollen failed to germinate although pollen grains were attached to the papillae by aid of their waxy surface substances.
Radish ( Raphanus sativus L., 2 n = 18) has tuberous roots and is consumed globally. Breeders have developed different types of radish, including oil radish, silique radish, and leafy radish. Radish is a particularly important vegetable crop in
More than 65 different genotypes, including cultivars and inbred lines, from five cruciferous species (Brassica oleracea L., B. campestris L., B. napus L., B. juncea L., and Raphanus sativus L.) were tested for their in vitro response of leaf protoplasts. Protoplasts were cultured in three liquid media and the resulting colonies were placed on seven test regeneration media. Significant differences among the species were found in plating efficiency in the frequency of shoot regeneration. Two broad response groups were identified: 1) Cultivars from B. oleracea and B. napus—these generally yielded protoplasts that were able to divide, form colonies at high frequencies, and regenerate shoots at variable frequencies; and 2) cultivars of the other species evaluated, which typically exhibited low plating efficiencies and little, if any, shoot regeneration. Evaluation for the effect of the cytoplasmic constitution of a few B. oleracea breeding lines on in vitro performance indicated that protoplasts carrying the Ogura (R1) male-sterile cytoplasm regenerated shoots at slightly lower frequencies than the corresponding alloplasmic-fertile lines. Genotypes exhibiting high frequency of shoot formation in one medium also had efficient shoot regeneration in other media as well, while genotypes with low shoot regeneration responded consistently in the different media used. This consistency in response indicates that genotype plays a critical role in determining the success of leaf protoplast culture in the crucifers.
Self-incompatibility (SI) in Brassicaceae vegetables prevents self-pollination by recognizing self-pollens and rejecting them at the stigmatic surfaces. The S-haplotypes of 47 hybrid radish cultivars that are commercially available in Korea were classified and identified using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Twelve kinds of S-haplotypes were identified from the cultivars: S 1 , S 8 , S 11 , S 17 , S 18 , S 30, and S 31 haplotypes in class-I S-haplotype and S 4 , S 5 , S 13 , S 21, and S 26 haplotypes in class-II S-haplotypes. Even though the class-II S-haplotypes are supposed to exhibit weak and/or leaky SI activity, the class-II S-haplotypes showed the same allele frequency of class-I S-haplotypes in 38 fully classified commercial cultivars. The SI activity was examined using the pollen tube germination test, flower pollination test, and the seed set ratio analysis. The pollen tube test showed low correlation (R 2 = 0.13) with the flower pollination test, a conventional method. The results of seed set ratio analysis varied from 0% to 159%, and thus could distinguish the weak and strong SI activity clearly and showed high correlation with the flower pollination test (R 2 = 0.69). The seed set ratios of the cultivars possessing the class-I/class-I, class-I/class-II, and class-II/class-II genotypes were 0.6%, 17.4%, and 38.1%, respectively. Among the eight class-II/class-II cultivars, three cultivars showed strong SI activity. The SI activity of the S 4 S 17 , S 5 S 8, and S 4 S 26 genotypes varied among cultivars, but the S 1 S 17 , S 5 S 17, and S 8 S 26 genotypes showed constant strong, intermediate, and strong activity, respectively, among the cultivars. Results indicate that the SI activity of Brassicaceae vegetables depends not only on the S-haplotypes, but also on the genetic background of cultivars.
Greenhouse experiments were carried out to determine the tolerance of two radish cultivars to soil-applied B, Mo, and Zn. Sources used were boric acid (0, 54, 108, 216, 324, and 432 ppm), molybdic acid (0, 1.4, 2.8, 5.6, 8.5, and 11.3 ppm), and zinc sulfate (0, 40, 80, 160, 240, and 360 ppm) applied at planting in addition to the control. Plants were grown in plastic containers of 1.5 L, filled with a potting medium composed of 50% vermiculite, 30% sphagnum peat, and 20% perlite. Treatments were arranged within a randomized complete block design with six replications. Fresh weight of commercial roots was not affected by Mo or Zn applications in either cultivar. However, B applications decreased root fresh weight as rate increased. These results suggest that these radish cultivars perform well in a relatively wide range of Mo and Zn application rates, whereas tolerance to B appears to be low.