factories. The seeds are sown on sponge mats, and when the hypocotyls elongate to 5 cm and the cotyledons open, the sprouts are packed in sealed containers and transported to market over Japan. In the store, the cotyledons may start to curl, which causes
Yusuke Kubo, Shinobu Satoh, Haruka Suzuki, Toshinori Kinoshita, and Nobuyoshi Nakajima
Yeh-Jin Ahn and Grace Qianhong Chen
, including endosperm, embryo root, hypocotyl, and cotyledon. We found that hypocotyl ( Ahn et al., 2007 ) and cotyledon (this report) were capable of producing adventitious shoots from cortex tissues at similar rates (≈24 and 25 shoots per explant
Nebahat Sari, Emily Silverman, Danny Reiland, and Todd C. Wehner
shown in Table 1 . Table 1. Seed characterization, seed and cotyledon measurements for 163 Lagenaria accessions. Each accession was classified for five important qualitative traits following the standards of the descriptor list published by the
Shahraban Bastaki, Mostafa AboEl-Nil, and Mahdi Abdal
Eggplant (Solanum melonga L.) cotyledons were used to form somatic embryos for somaclonal induction and for selection of salt tolerant genotypes in a genetic improvement program. Naphthalene acetic acid at concentrations ranged from 5 uM to 85 uM induced embryogenesis when cultures were incubated under 16 hrs of light photoperiod. NAA was the only growth regulator required, and the addition of kinetine and benzyl adenine inhibited embryo formation. High frequency embryogenesis formed in 2 week old cotyledons when cultured on a medium supplemented with 43 uM NAA. Data showed that varieties varied in their embryogenesis potential and that cotyledons were the most responsive tissue. Somatic embryos germinated into plantlets when transferred into media without any growth regulators. Somatic embryos were plated on germination media supplemented with Kuwait brackish water to increase the total dissolved salts in the medium from 4,770 ppm to 30,000 ppm in seven equal increments. Brackish water at all concentrations caused embryos to revert into profuse callus growth.
Christopher C. Dickinson, Alexandra J. Weisberg, and John G. Jelesko
Bio-Rad (Richmond, CA) Biolistic PDS-1000 He Particle Delivery System. Poison ivy cotyledon/first true leaf-stage seedlings in magenta boxes were subjected to particle bombardment at a distance of ≈13 cm. After bombardment, plants were returned to a 28
Yu-Tsung Lin, Chia-Wei Lin, Chien-Hung Chung, Mei-Hsiu Su, Hsiu-Yin Ho, Shi-Dong Yeh, Fuh-Jyh Jan, and Hsin-Mei Ku
, 1993 ; Tang and Punja, 1989 ). The frequency of shoot formation in C. metuliferus PI 292190 from petiole explants was 14.6% ( Raharjo and Punja, 1993 ); however, 0% to 30% from leaf explants and 0% to 10% from cotyledon explants were observed ( Punja
Pinki Devi, Scott Lukas, and Carol A. Miles
et al., 2012 ; King et al., 2008 ; Kubota et al., 2008 ; Louws et al., 2010 ; Taylor et al., 2008 ). Grafted watermelon transplants are expensive due in part to the grafting methods that are commonly used for this crop, the one-cotyledon and hole
G.G. Ning and M.Z. Bao
the successful regeneration of plants from cultures of P. mume . This article presents the first report of the successful regeneration of plants of P. mume achieved through indirect organogenesis from cotyledons of immature embryos. In the course
Keith S. Mayberry, Kent J. Bradford, and Vincent E. Rubatzky
A seedling disorder of broccoli (Brassica oleraceae L. var. italica) characterized by chlorotic cotyledons and delayed seedling growth is described. This disorder, termed “yellow cotyledon”, has been observed in field plantings under high temperatures with some broccoli seed lots. Yellow-cotyledon disorder can be observed in laboratory germination tests if they are conducted under illumination, where unaffected seedlings will develop green cotyledons. Little relationship was found between overall seed vigor and the expression of yellow cotyledon by use of early germination counts and accelerated aging tests, although the most severely affected seed lots had been stored for several years. Field trials in 2 years showed that although seedlings with yellow-cotyledon disorder developed into normal plants, maturity was delayed and total yields were reduced.
N.M.P. Guedes and P.H. Jennings
To improve somatic embryogenesis of Cucumis sativus, two types of explants (cotyledons and stem sections) were cultured on Murashige and Skoog (MS) media supplemented with 2,4-D (2.0 mg·L–1) + kinetin (0.5 mg·L–1). After 4 weeks, the embryogenic callus was transferred for 2 weeks to MS + NAA (1.0 mg·L–1) for embryo development. Stem sections failed to develop embryos while cotyledons responded with 14% embryo formation. The embryos were transferred to MS without hormones for 4 weeks to allow for plantlet growth. These embryos developed only shoots. To improve on the successful generation of embryos with root and shoot development, the procedures used above were repeated, but the cotyledons were cut into three sections to be used as explants. Each transverse section of the cotyledon was approximately 2–3 mm wide. All sections produced callus but not all of them were embryogenic. From the first section (cotyledon base), the second (between the first and third section) and the third section (furthest from the cotyledon base), respectively, 58%, 31%, and 5% embryo development occurred. Those embryos from the basal cotyledon sections regenerated 10 plantlets, 5 with shoots and roots and 5 with only shoots. Approaches to enhance somatic embryogenesis, and shoot and root development, will be discussed.