FR2654579A1 - Sterile male hybrid variety of black tobacco "ITB1000" intended for the industrial production of tobacco leaves - Google Patents

Abstract

New plant production of black tobacco. The invention relates to a new sterile male F1 hybrid variety of black tobacco. It was obtained by crossing between the sterile male tobacco variety "MS A1", maintained by fertilisation with the fertile variety "A1", and the fertile tobacco variety "PB 523" maintained by self-fertilisation. It is mainly characterised by the purplish-red colour (ref. RHS 62-B) of its flowers, an angle of about 45 DEG of its leaves, a good combined resistance to known tobacco diseases, a greater precocity, a yield and a combustibility which are superior to those of known varieties, a "green index" permitting an improved colour of the dry tobacco. The invention is particularly suitable for exploitation in industrial cultivation for the production of tobacco leaves.

Description

The present invention relates to a hybrid F1 male sterile variety of Black Tobacco, identified by the name "ITB 1000", intended for the tobacco industry and which differs from known varieties of its species by the unique combination of the following characteristics:
- purplish red flower color (RHS 62-B);
- leaf angle of about 45 degrees which gives the variety an upright habit;
- greater precocity: the "ITB 1000" variety flowers and ripens 5 to 7 days earlier than the reference black tobacco variety PB D6;
- excellent resistance (or tolerance) to diseases: downy mildew (Peronospora tabacina), black root rot (Chalara elegans), potato virus Y and tobacco mosaic virus;
- yield (3270 kg / ha) and combustibility (74/100) superior to known varieties of black tobacco;
- weak "green index" (150.9) allowing better coloring of dry tobacco.

 Taking into account the characteristics listed above and in particular the precocity, the present invention responds in a particularly efficient manner to the needs of the tobacco industry in particular with regard to the coloring of the raw material extracted from plants of the variety.

 The aim of the research carried out was in fact to create a new variety making it possible to improve the quality of the raw material of PB D6 tobacco, particularly in terms of its coloring. Precocity was also one of the objectives sought as a criterion favorable to obtaining such a raw material.

 The present invention results from the crossing between on the one hand the variety MS Al, a sterile male tobacco, held in reference collection by the applicant, whose agronomic and industrial characteristics are very close to those of the reference variety PB D6 and d on the other hand, a stabilized line identified by the name PB 523, itself resulting from a selection made by the inventors and held in the reference collection by the applicant.

 The aforementioned sterile male parent MS Al has a cytoplasm from Nicotiana Suaveolens. Obtained by inter-specific hybridization, it was selected for its industrial qualities during seven (7) successive backcrosses. It is currently fixed.

 The invention constituted by the hybrid F1 resulting from the crossing between the two aforementioned parents was carried out for the first time in 1986 and was tested in small plots in 1987 then in field of comparison in 1988 and 1989. From 1987 the hybrid F1 constituting the present invention proved to be the best among ten (10) male-sterile F1 compared to PB D6 tobacco chosen as reference variety: higher yield than the reference variety itself and very high appraisal rating . These results were confirmed in 1988 and led to the conclusion that the variety obtained as indicated above is of definite interest for the tobacco industry.

 Anyone skilled in the art can reproduce the hybrid sterile male variety F1 "ITB 1000" which is the subject of the present invention by crossing between on the one hand the sterile male variety of the applicant "MS Al", itself maintained by fertilization with the fertile variety of Applicant "ai", and on the other hand the fertile variety "PB 523" (fertile partner of the hybrid F1) whose properties are maintained by self-fertilization. The three lines MS Al, Al and PB 523 have been deposited by the applicant and are maintained at the Technical Institute of Tobacco, Domaine de la Tour in Bergerac.

DESCRIPTION
The description below is based on observations of tobacco plants grown in Bergerac, France. The color connotations used below are those used in the Color Map of the RHS (Royal Horticultural Society) itself used by the experts of the International Convention for the Protection of New Varieties of Plants. This description is made according to the criteria defined by CORESTA (Dr. N. Anitia and Ing. I.

Ioan): "the fundamental morphological characteristics for the botanical description of tobacco" (CORESTA Bulletin, 19860, 4, 17-32). Plants of the variety were described in August and
September 1989. Any slight differences which may appear depending on the conditions of the ambient climate and the terrain are not liable to modify the combination of the essential characteristics of the present invention.

 The sterile male F1 hybrid "ITB 1000" constituting the present invention is a developed tobacco. The plant flowers at a height of around 160 cm. It has 20 leaves, the largest having, on adult tobacco, 58 cm long and 35 cm wide on average. Its internodes are quite short.

 Figure 1 shows the external morphology of the flowers and shows an aborted, unfertilized capsule.

 Figures 2 to 4 respectively represent the lower leaves, the middle leaves and the head leaves.

 Figure 5 shows the general habit of the plant.

 The plant has a conical shape, like most tobacco in its category. The leaves are inserted on the stem at an angle of about 45 degrees, which gives the "ITB 1000" a fairly upright habit. The convex leaf blade is slightly arched.

The leaf has an elliptical shape.

 The base of the leaves is decurrent and has symmetrical auricles.

 The flowers are clearly distinguishable from those of other black tobacco grown in France, by their color Purplish Red (RHS 62-B).

 Like PB D6, the reference variety, the plant has a sustained habit, characteristic of air-dried brown tobacco.

 In 1988 and 1989, it presented an excellent sanitary state.

Compared to other black tobacco grown in France, the "ITB 1000" is with PB D6 the one that associates the most resistance (or tolerance) to diseases: tobacco mildew (Peronospora
Tabacina), black root rot (Chalara Elegans), virus
Potato Y and tobacco mosaic virus.

 It has been cultivated in comparison with PB D6 since 1987.

The results of the comparisons made are shown in the table below.
Variety Yield Combustibility Rating Alkaloids Index
(kgha) (o to 100) total% ms green PB D6 2945 70.4 62 3.12 192.1
ITB 1000 3270 74.0 64 3.12 150.9
In the preceding table, the term "combustibility" should be understood to mean the speed and regularity of combustion of the central part of the leaf blade; "rating" means the rating of experts estimated from a series of criteria for coloring, character or nature of the fabrics, length of leaves and combustibility, said rating ranging from 0 to 100; ; "green index", a direct measurement on tobacco powder by reflectano spectrophotometry of chlorophyll residues.
It appears that the variety "ITB 1000" is superior to PB D6 in terms of yield and its rating (attributed during the appraisal of the raw material). Its combustibility is also slightly better than that of the reference. The lower Green Index reflects better coloring of dry tobacco, a recognized quality criterion.

Claims (2)

1) New and distinct hybrid F1 male-sterile variety of black tobacco, "ITB 1000", identified by the characters described above and by the samples deposited and maintained in the collection of the Technical Institute of Tobacco in Bergerac, characterized by the following new and unique combination of morphological and physiological characters: plant of average height of 160 cm with 20 harvestable leaves reaching on the adult plant 58 cm long and 35 cm wide on average; supported plant with a conical shape; leaves with an angle on stem of about 45 degrees; purplish red flowers (RHS 62B); very good resistance combined with downy mildew (Peronospora tabacina), black root rot (Chalara elegans), potato virus Y and tobacco mosaic virus; yield (kg per hectare) of 3270; combustibility (0 to 100) of 74.0; very low green index (150.9) allowing better coloring of dry tobacco. 2) As new industrial products, tobacco plants of the variety according to claim 1) as well as the leaves from said plants and the raw material extracted from said leaves.