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221.
Recovery of doubled haploid (DH) progeny from haploid melon plants for use in breeding programs requires efficient chromosome
doubling procedures. We describe improved procedures for recovery of fruits and viable seeds from parthenogenetic melon plants.
Plant regeneration from nodal explants treated with 500 mg/L colchicine for 12 h was increased from 40 to 88% by transferring
the treated explants to medium supplemented with a combination of growth regulators [5 μM IAA; 5 μM BA; 1 μM ABA; 30 μM AgNO3). Prolonged exposure (2–7 days) to colchicine inhibited regeneration from nodal explants but had less effect on shoot tip
explants. Many colchicine-treated plantlets flowered in vitro, allowing early assessment of their male fertility. Production
of stained pollen in plants from nodal explants was highest after 0.5–2 days of colchicine treatment and on plants from shoot
tips after 1–2 days. In vitro pollen counts correlated well with counts from greenhouse grown plants and with fruit set. The
fruit set rate for colchicine-treated plants with a high pollen number was 47%. Appropriate colchicine treatment and culture
of nodal explants as well as tip explants can substantially increase the number of fertile plants and DH lines recovered from
parthenogenetic melons. 相似文献
222.
Thomas Geier 《Plant Cell, Tissue and Organ Culture》1986,6(2):115-125
Regeneration from Anthurium scherzerianum leaf segments was found to be highly dependent on genotype and leaf age. Of the various medium factors tested, the NH4NO3 level had the most significant effect on callus and shoot formation from leaf tissue. A low level of NH4NO3 (200 mg/l) proved beneficial to the induction of regeneration in all genotypes investigated. As compared to induction, multiplication of callus and shoots in subcultures was less susceptible to the action of various medium factors. After isolation from callus, shoots readily formed roots in the absence of growth regulators. High NH4NO3 level (720 mg/l) strongly accelerated root formation. Rooting ability progressively decreased as a consequence of repeated shoot multiplication in the presence of benzyladenine (BA) as sole growth regulator. The advantages and limitations of different micropropagation schemes are discussed. 相似文献
223.
224.
The time course of the specific activities of UDP-D-glucuronate decarboxylase (E.C. 4.1.1.35) and UDP-D-xylose 4-epimerase (E.C. 5.1.3.5) have 相似文献
225.
SYNOPSIS. When transformed procyclic noninfective trypanosomes of several unrelated stocks of Trypanosoma brucei were cultivated in T-30 Falcon flasks at 28 C in a liquid medium containing head-salivary gland explants of Glossina morsitans morsitans some of the organisms developed into forms infective for mice. Infective trypanosomes were detected 7 to 14 days after the cultures were prepared and they persisted for varying periods of up to 88 days when the cultures were terminated. A few of the salivary glands became invaded with parasites about the time infective organisms appeared in the cultures. Using T. brucei TREU 929, it was shown that trypanosomes grown with between 27 and 50 explants were capable of producing infections consistently for prolonged periods. On the other hand, trypanosomes cultivated with 25 or fewer explants rarely infected mice. Infectivity titrations on trypanosome suspensions from cultures of stocks TREU 1275 and TREU 929 revealed that the maximum number of infective organisms was present 26 to 50 days after initiation of the cultures. Control cultures of trypanosomes grown in medium alone were generally not infective but 2 of the 6 stocks gave rise to a few sporadic infections. A few epimastigote-like and metacyclic-like trypanosomes were seen in stained preparations of infective inocula. 相似文献