HYBRIDIZATION BETWEEN BETA VULGARIS AND B. PROCUMBENS AND TRANSMISSION OF NEMATODE (HETERODERA SCHACHTII) RESISTANCE TO SUGARBEET

1975 ◽  
Vol 17 (2) ◽  
pp. 197-209 ◽  
Author(s):  
Helen Savitsky
Keyword(s):  
Beta Vulgaris ◽  
Transmission Rate ◽  
Nematode Resistance ◽  
Heterodera Schachtii ◽  
Backcross Generation ◽  
Pollen Mother Cells ◽  
Average Transmission ◽  
Mother Cells

Triploid hybrids between tetraploid Beta vulgaris (4x = 36) and diploid B. procumbens (2x = 18) were used to transmit nematode resistance into sugarbeet. In meiosis of triploid hybrids, nine B. vulgaris bivalents and nine B. procumbens univalents were usually observed. In some pollen mother cells (PMC's) trivalent associations (8II + 8I + 1III) were formed. The second anaphase varied from near regular to very irregular. The regular anaphase produced normal quartets and viable gametes.The B1 plants and the plants of all succeeding backcross generations were tested for nematode resistance. From 6,750 B1 plants, four nematode-resistant trisomics were selected that had 18 B. vulgaris chromosomes and one B. procumbens chromosome responsible for resistance. The B. procumbens chromosome and nematode resistance were transferred to the eighth backcross generation with an average transmission rate of 12%. In meiosis of trisomies, trivalent associations of two B. vulgaris and one B. procumbens chromosomes were formed in a few PMC's. Two diploid nematode-resistant plants were selected from 8,834 backcross plants in the progenies of trisomies, and resistance was transferred from both of these plants to F1 hybrids. The segment of the B. procumbens chromosome bearing the gene for nematode resistance has been transferred to a sugarbeet chromosome.

NEMATODE (HETERODERA SCHACHTII) RESISTANCE AND MEIOSIS IN DIPLOID PLANTS FROM INTERSPECIFIC BETA VULGARIS × B. PROCUMBENS HYBRIDS

1978 ◽  
Vol 20 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Helen Savitsky
Keyword(s):  
Beta Vulgaris ◽  
Transmission Rate ◽  
Nematode Resistance ◽  
Heterodera Schachtii ◽  
Next Generation ◽  
Pollen Mother Cells ◽  
Transmission Rates ◽  
Male Gametes ◽  
Mother Cells ◽  
Lower Frequencies

Three diploid nematode-resistant plants derived from hybrids between Beta vulgaris L. and B. procumbens Chr. Sm. were crossed with diploid nematode-susceptible plants. The rates of resistance transmission from the F1 hybrids to the F2 varied from 7 to 27%. The transmission rate of F2 plants derived from F1 plants with transmission rates over 20% averaged 20.9%. The rate for F2 plants derived from F1 plants with transmission rates of 10% or lower averaged 11.3%. In diploid plants nematode resistance was transmitted through the pollen at lower frequencies than through egg cells. Transmission through female gametes varied from 11.0 to 31.4% and through male gametes of the same plants from 0 to 19.7%. In some pollen mother cells (PMCs) of diploid nematode-resistant plants meiosis was normal and gametes derived from these cells transmitted resistance to the next generation. Abnormalities were observed in other PMCs, including the detachment of the B. procumbens segment from the translocated chromosome, the formation of bridges, and the lagging of broken translocated chromosomes. The inadequate transmission of resistance was caused by a loss of the B. procumbens segment in some B. vulgaris bivalents.

Disomic and ditelosomic alien chromosome additions in beet (Beta vulgaris), carrying an extra chromosome of B. procumbens or telosome of B. patellaris

Genome ◽  
1993 ◽  
Vol 36 (2) ◽  
pp. 261-267 ◽  
Author(s):  
W. Lange ◽  
Th. S. M. De Bock ◽  
G. J. Speckmann ◽  
J. H. De Jong
Keyword(s):  
Beta Vulgaris ◽  
Germ Line ◽  
Extra Chromosome ◽  
Chiasma Formation ◽  
Cyst Nematode ◽  
Heterodera Schachtii ◽  
Alien Chromosome ◽  
Chromosome Transmission ◽  
Female Germ Line ◽  
Mother Cells

Alien chromosome transmission through the female germ line as well as meiosis in pollen mother cells were studied in disomic and ditelosomic alien chromosome additions of beet. Beta vulgaris, carrying an extra pair of chromosomes or telosomes of B. procumbens or B. patellaris, respectively. The alien chromosomes carried genes for resistance to the beet cyst nematode, Heterodera schachtii, and screening for this resistance was used to select plants with or without the alien chromosomes. A great variation for alien chromosome transmission was recorded and plants carrying two extra alien chromosomes were recovered in the backcross progenies of the disomic or ditelosomic additions. However, in these progenies the average frequencies of plants without alien chromosomes (86%) did not clearly differ from that in similar progenies of the original monosomic or monotelosomic chromosome additions, indicating that doubling the number of the alien chromosome did not enlarge their transmission to the next generation. The alien chromosomes fully paired at pachytene and desynapsed again before diakinesis, indicating decreased chiasma formation. At second metaphase nearly 60% of the cells had one extra chromosome, and the remaining cells carried two or no extra chromosomes in about equal proportions. The tetrads looked fully normal. The expected relation between the average number of alien chromosomes in the germ cells and in the plants of the progenies did not show up, indicating a strong selection favouring the female gametes without alien chromosomes.Key words: disomic and ditelosomic alien chromosome additions, Beta vulgaris, Beta procumbens, Beta patellaris, chromosome transmission, meiosis.

Association of a nematode resistance bearing addition chromosome with a recurring leaf intumescence somaclonal variation in sugar beet

Genome ◽  
1991 ◽  
Vol 34 (3) ◽  
pp. 477-485
Author(s):  
M. H. Yu ◽  
L. M. Pakish ◽  
J. W. Saunders
Keyword(s):  
Sugar Beet ◽  
Somaclonal Variation ◽  
Beta Vulgaris ◽  
Chromosome Doubling ◽  
Nematode Resistance ◽  
Heterodera Schachtii ◽  
Regenerated Plants ◽  
Alternative Expression ◽  
Monosomic Addition

Intumescent leaf variants of sugar beet (Beta vulgaris L.) were obtained through callus culture of a monosomic addition that carried resistance to Heterodera schachtii Schm. The frothy pockmarked appearance of the leaf surface was due to hyperplastic growth of the mesophyll and epidermal cells. The epidermis had many malformed stomata. Veins were underdeveloped, but protrusions beneath were pronounced. Intumescence occurred in 20.3% of the regenerated plants and it was heritable to F1 and later progeny. Leaf intumescence is a new phenotype for Beta. About 73.5% of regenerants contained the donor somatic chromosome number, the remainder were doubled or mixoploids, with no chromosome losses apparent. The 38-chromosome intumescent plant represents a dual somaclonal variation, chromosome doubling and leaf intumescence. Progeny of the 19- and 38-chromosome intumescent plants intercrossed or pollinated by diploids or tetraploids had 9, 18, 19, 27, 28, 29, 36, 37, 38, or 39 chromosomes. All intumescent plants were aneuploids with the monosome addition. There were linkages for leaf intumescence (Li), resistance to H. schachtii (Hs), and hypocotyl color (Rpro) on the addition chromosome. The efficacy of Hs remained intact through the in vitro culture and succeeding crosses. The Li-bearing plants manifested depressed growth and markedly reduced seed set. Leaf intumescence was thought to be the alternative expression of galling potential of Beta procumbens Chr. Sm. germ plasm.Key words: somaclonal variation, leaf intumescence, nematode resistance, monosomic addition, Beta vulgaris L.

Breeding and usage of sugar beet cultivars and hybrids resistant to sugar beet nematode Heterodera schachtii

2015 ◽  
Vol 2 (1) ◽  
pp. 12-22 ◽  
Author(s):  
L. Pylypenko ◽  
K. Kalatur
Keyword(s):  
Sugar Beet ◽  
Sugar Content ◽  
Production Capacity ◽  
Nematode Resistance ◽  
Control Measures ◽  
Heterodera Schachtii ◽  
Yield Reduction ◽  
Agricultural Practice ◽  
Germplasm Exchange ◽  
Good Agricultural Practice

Heterodera schachtii Schmidt, 1871 is one of the most economically important pests of sugar beet (Beta vulgaris L.) worldwide. It is also widespread in most sugar beet growing regions in Ukraine causing serious yield reduction and decreasing sugar content of sugar beet in infested fi elds. An advanced parasitic strategy of H. schachtii is employed to support nematode growth, reproduction and harmfulness. In intensive agriculture systems the nematode control measures heavily rely on nematicides and good agricultural practice (crop rota- tion in the fi rst place). But alternative strategies based on nematode resistant sugar beet cultivars and hybrids are required as none of nematicides approved for the open fi eld application are registered in Ukraine. Here we review the achievements and problems of breeding process for H. schachtii resistance and provide the results of national traditional breeding program. Since the beginning of 1980s fi ve sugar beet cultivars (Verchnyatskyi 103, Yaltuschkivska 30, Bilotcerkivska 45, BTs-40 and Yuvileynyi) and seventeen lines partly resistant or toler- ant to H. schachtii have been obtained throughout targeted crossing and progenies assessment in the infested fi elds. The further directions for better utilization of genetic sources for nematode resistance presented in na- tional gene bank collection are emphasized. There is a need for more accurate identifi cation of resistance genes, broader application of reliable molecular markers (suitable for marker-assisted selection of nematode resistant plants in the breeding process) and methods for genetic transformation of plants. Crop cash value and national production capacity should drive the cooperation in this fi eld. Knowledge as well as germplasm exchange are thereby welcomed that can benefi t breeding progress at national and international level.

An Effective Congestion Control Algorithm based on Traffic Assignment and Reassignment in Wireless Sensor Network

2020 ◽  
Vol 13 (8) ◽  
pp. 1166-1174
Author(s):  
Chao Wang
Keyword(s):  
Wireless Sensor Network ◽  
Congestion Control ◽  
Sensor Network ◽  
Traffic Assignment ◽  
Transmission Rate ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Congestion Detection ◽  
Detection Technology ◽  
Average Transmission

Background: It is important to improve the quality of service by using congestion detection technology to find the potential congestion as early as possible in wireless sensor network. Methods: So an improved congestion control scheme based on traffic assignment and reassignment algorithm is proposed for congestion avoidance, detection and mitigation. The congestion area of the network is detected by predicting and setting threshold. When the congestion occurs, sensor nodes can be recovery quickly from congestion by adopting reasonable method of traffic reassignment. And the method can ensure the data in the congestion areas can be transferred to noncongestion areas as soon as possible. Results: The simulation results indicate that the proposed scheme can reduce the number of loss packets, improve the throughput, stabilize the average transmission rate of source node and reduce the end-to-end delay. Conclusion: : So the proposed scheme can enhance the overall performance of the network. Keywords: wireless sensor network; congestion control; congestion detection; congestion mitigation; traffic assignment; traffic reassignment.

Chromosome localization of genes that control synchronous development of pollen mother cells in wheat

Caryologia ◽  
2003 ◽  
Vol 56 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Wei Li ◽  
Jun Yang ◽  
You-Fu Pan ◽  
Guang-Qin Guo ◽  
Guo-Chang Zheng
Keyword(s):  
Chromosome Localization ◽  
Pollen Mother Cells ◽  
Synchronous Development ◽  
Mother Cells

An ultrastructural study of cytomixis in tobacco pollen mother cells

PROTOPLASMA ◽  
2011 ◽  
Vol 248 (4) ◽  
pp. 717-724 ◽  
Author(s):  
Sergey R. Mursalimov ◽  
Elena V. Deineko
Keyword(s):  
Ultrastructural Study ◽  
Pollen Mother Cells ◽  
Tobacco Pollen ◽  
Mother Cells

Persisting demibivalents: a unique meiotic behaviour in Cuscuta babylonica Choisy

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 63-66 ◽  
Author(s):  
Batia Pazy ◽  
Uzi Plitmann
Keyword(s):  
Key Words ◽  
Chromosome Segregation ◽  
Meiotic Behaviour ◽  
Chromosome Behaviour ◽  
Chromosome Movement ◽  
Pollen Mother Cells ◽  
Key Words Meiosis ◽  
Mother Cells ◽  
Telomeric Association

Idiosyncratic chromosome behaviour during meiosis was found in pollen mother cells of Cuscuta babylonica Choisy, a thread-like holoparasitic herb. Its main features are among the following: (i) telomeric association between homologues through most stages of the process, which leads to persisting chromatid bivalents (= "demibivalents"); (ii) uncommon chromosome segregation in first and second anaphase; and (iii) prolonged intensified heterochromatinization. Although "regular" in its own way, this process leads to the formation of unviable products. Its further investigation might contribute to our understanding of the role of the spindle and chromosome movement in the ordinary process of meiosis. Key words: meiosis (abnormal), persisting demibivalents, Cuscuta babylonica.

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