CROP BREEDING AND IMPROVEMENT

Plant breeding is the science of changing and improving the heredi­ty of plants.

In the past the breeders had no scientific knowledge which is ava­ilable now. The selection of superior types was the most important me­thod of improving crop plants. Variations between plants of the same species were used as the basis for developing new improved varieties.

 

 

36

Now with increased knowledge of genetics and related plant scien­ces plant breeders are able to influence such plant characteristics as yield, early maturity, drought resistance, winter hardiness, disease re­sistance, insect resistance and quality.

Plant breeding depends on many sciences, genetics and cytogene­tics being the two most important. Other sciences needed by the bree­ders are plant physiology, plant pathology, entomology, plant biochemis­try, agronomy, botany, statistics and computer science. The most suc­cessful achievements in plant breeding are due to the combined work of many specialists.

Each crop variety possessing certain desirable and undesirable cha­racteristics, the aim of the plant breeder is the development of a supe­rior variety by eliminating the undesirable qualities and combining the desirable ones in the same variety.

The characteristics desired vary with¹ the crop and the conditions of growing. With wheat, for example, winter hardiness, protein content, milling quality and resistance to lodging are important. In some areas, early-maturing, cold-resistant varieties are needed, while in others la­ter-maturing, drought-resistant varieties will do best, yield and resistan­ce to major diseases and insects being important in all cases.

Three general methods of crop improvement are commonly used. These are introduction, selection and hybridization, the last one being the method of crossing two or more varieties that differ in some inheri­ted characters. These methods are not wholly distinct because hybridi­zation almost always must be preceded or followed or both preceded and followed by some scheme of selection.

Progress in crop breeding can be measured only by experimental tests except when breeding is done for disease resistance, better colour or some other character that can be readily seen. Even then the inves­tigator must know how the new strain compares in yield with the vari­ety replaced. That is why field-plot test² should be conducted.

Пояснения к тексту

1) to vary witii — различаться в зависимости от; зависеть от;

2) field-plot tests — испытания на делянках в поле.

 

 

37

 

Лексический минимум к тексту А

to breed, plant breeding, plant breeder, selection, hybridisation, in­troduction, species, to cross, winter hardiness, maturity, disease, insect drought, science, desirable, succesaful, to precede, to follow, to differ (in), to compare, to vary with, available, to change, early, late, that.

АУДИТОРНАЯ РАБОТА

VI. Выборочная проверка упражнений из задания на дом № 1.

VII.      Сгруппируйте слова по частям речи (существительное;
прилагательное; глагол; причастие I, II; наречие) (устно):

gradually, abundant, aggregated, lower, competition, properly addi­tional, seeder, to decrease, poorer, directly, desirable, careful, limiting, suitable, requirement, removed, maintenance, wider, mixture, mechani­cal, physiologist, harrowed, favouring, fixer, to destroy, finest, follower.

VIII.Укажите предложения, содержащие независимый причастный оборот. Переведите предложения (устно).

1. Plant breeding being the science of changing the heredity of plants, the scientists widely use it in improving crop plants. 2. Many plant sci­ences are used by plant breeders in developing new varieties of crops, genetics and cytogenetics being most important. 3. Many varieties of corn producing good yields of high quality forage and grain are cultiva­ted throughout our country. 4. Each plant has two parts, the roots and the above-ground portion, the latter consisting of leaves and stems. 5. The stem of corn varies greatly in length in different varieties, the usual length being 5 to 10 feet. 6. Planting machines being used, a smaller amount of seed is required.

IX. Назовите номера предложений, в которых слово that эквивалентно русскому "который" (устно).

1. The climate of Moscow is colder than that of Krasnodar. 2. We know that millets belong to the grass family. 3. That experiment was conducted two years ago. 4. The experiment that was conducted two years ago gave very good results. 5. The optimum temperature for cotton is higher than that for small grains. 6. It has been shown by experiments that the quality of grain depends on the soil used. 7. The variety of wheat that will be grown on our farm is highly productive. 8. We need a good soil for our experiment, that is, the one that is suppli­ed with the necessary amount of water and nutrients. 9. Corn is a

 

 

38

good source of grain and forage: that is why it is widely grown by farmers.

X. Перечислите признаки растений, которые можно изменять
с помощью селекции (по-английски, устно).

XI. Контроль чтения и понимания текста А.

Задание на дом № 2

XII. Употребите вместо пропусков слова из текста А в соответствующей форме (письменно):

1. Improving ... of crop plants is the aim of the science known as
plant breeding. 2. Early ... is a highly important plant characteristic in
areas where the growing period is short. 3. Winter cereals should with-
stand fall and spring frosts, that is, they should possess.. 4. The

most... breeding work has been done in improving corn. 5. The aim of ... or the crossing of two or more varieties is obtaining a hybrid ... better inherited characteristics. 6. Very often high yields of good-quality grain can be produced due to ... of superior varieties from other regions or

other countries. 7. Rye being a plant, any class of soil may be used

in growing this crop. 8. Selection should ... and ... hybridization.

XIII.     Составьте предложения, соединяя части, подходящие по
смыслу (письменно):

1. At present plant breeders can improve a) where summers are short;

2.Early-maturing, cold-resistant            b) with the biological characteris-varieties are grown        tics of the crops grown;

3. Practical experience of our best          c)crop yield and quality;

collective farms shows that

4. Yields vary                                 d) of all seed plants;

5. Hybridization is used in the                e) there are great reserves of
improvement                              increasing crop yields.

XIV.     Переведите следующие предложения на английский язык
(письменно):

а) 1. Наследственность растений можно изменить. 2. Селек­ционеры выводят новые сорта. 3. Знание генетики необходимо для выведения новых сортов. 4. При выведении нового сорта исполь­зуются достижения многих наук. 5. В некоторых условиях жела­тельными признаками пшеницы являются зимостойкость и устой­чивость к полеганию. 6. Гибридизация — это метод получения нового сорта скрещиванием двух или более сортов.

 

 

39

б) 1. Наследственность растений можно изменить и улучшить селекцией. 2. Раньше улучшение растений и выведение новых со­ртов производилось путем отбора лучших типов. 3. Сейчас мно­гие признаки растений, такие, как урожайность, зимостойкость, засухоустойчивость и другие, успешно улучшаются нашими се­лекционерами. 4. Для выведения новых сортов нужно использо­вать достижения многих наук. 5. Новый улучшенный сорт можно вывести скрещиванием двух или более сортов, соединяя желатель­ные признаки в одном сорте. 6. Каждый сорт, выведенный для данных климатических условий, обладает определенными полез­ными признаками.

XV.      Выполните лабораторную работу № 2.

АУДИТОРНАЯ РАБОТА

 

XVI. Проверка домашнего задания.

 XVII.Переведите следующие группы слов (устно):

for instance, lodging resistant varieties, a major crop production problem, one of he main controlling measures, plant breeding, plant breeder, winter hardiness, to eliminate undesirable characteristics, high disease resistance,
to develop a variety, a superior variety, dorught-resistant variety, general crop improvement methods, the same variety.

XVIII.  Составьте предложения, используя сочетания слов из
упражнения XVII (устно).

XIX.Ответьте на следующие вопросы к тексту Л (устно):

1. Can the heredity of plants be changed? 2. What was the main method of improving crop plants in the past? 3. What plant characteris­tics can be improved by breeding? 4. How can a superior variety be developed? 5. What do desirable plant characteristics vary with? 6. What are the three general methods of crop improvement? 7. What is hybridization?

XX. Прочтите текст В, не пользуясь словарем, догадайтесь о
значении выделенных слов.

 

40

Text В

A NEW HYBRID

A new hybrid has been developed by crossing wheat and rye. It is the first man-made cereal named triticale. Its name comes from a com­bination of the scientific names for wheat, Triticum. and rye, Secale.

The aims of hybridization between the two crops are increasing protein content of wheat and combining high yields of wheat with dro­ught-resistance of rye.

The first hybrids between wheat and rye were obtained in 1875. But those hybrids were highly sterile and did not reproduce. Triticale as a variety was first produced in Hungary (Венгрия) in 1968. In North America the first variety of triticale was developed in 1970. A few thousand hectares of triticale were grown in the Soviet Union in 1973.

At present there are triticales that can be produced commercially. The crop is classed now as a feed grain. As such it is equivalent to other cereals. But the grain quality is not very good for bread making

Protein content of the hybrid can be 30 percent, compared to 8 or 10 percent in corn and 13- 5 percent in rye and wheat. Triticale protein is high in essential amino acids which make the crop very good as feed for livestock.

Plant breeders are now working at developing triticales with shor­ter stems that will not lodge. Much breeding work should be done in improving the grain quality and increasing the yield.

XXI.     Расположите вопросы так, чтобы они могли служить планом к тексту В.

1. What triticale characteristics should be improved?

2. What is triticale?

3. What are the uses of the crop?

4. Are there any varieties of triticale?

5. What characteristic makes triticale superior to wheat and rye?

6.  What are the aims of crossing wheat and rye?

XXII. Дайте оценку тритикале по сравнению с пшеницей и рожью (по-русски или по-английски) (устно).

 

41

LESSON 7

ГРАММАТИКА И ЛЕКСИКА:

1. Повторение причастий 1 и П.

2. Повторение -ing форм.

3. Условные предложения (союзы if, unless, provided).

4. Значения should.

5. Значения because, because of.

6. Значения before, after.

Задание на дом № 1

I. Проработайте в разделе "Грамматика и словообразование"
§11.

II. Из данных слов выделите прилагательные и причастия с
отрицательными приставками и суффиксами и дайте их русские
эквиваленты (устно):

unimportant, improper, useless, unimproved, unpopular, hardiness, uniform, impossible, internode, uninherited, careless, include, inactive, underground, undesirable, fruitless, unfavourable, undeveloped.

Ш. Переведите предложения, содержащие условные прида­точные (устно):

a) 1. If we grow legumes, the soil fertility will be higher. 2. Corn will grow better if there is much nitrogen in the soil. 3. If the seed is of high quality, we shall obtain a higher yield;

b) 1. If we grew legumes, the soil fertility would be higher. 2. Corn would grow better if there were more nitrogen in the soil. 3. If the seed had been of good quality, we should have obtained a higher yield.

IY. Найдите в следующих предложениях причастия и опреде­лите их функцию. Переведите предложения (устно):

a) 1. Using the new method of harvesting, they obtained higher yield of sugar beets. 2. The collective farms using the new method of harvesting obtain higher yield of sugar beets. 3. Our collective farm is harvesting sugar beets now. 4. The growing period of barley is shorter than that of other cereals, this crop producing good yield when it is sown in late May. 5. Rye being drought-resistant, any soil can be used for this crop.

b) 1. Most wheat varieties cultivated produce high yields of good quality grain. 2. Wheat varieties cultivated in our country have been

 

 

42

developed by our plant breeders. 3. Two wheat varieties are cultivated on the farm "Zarya";

с) 1. Having stored up nutrients in the first season, root crops are able to grow and produce seed in the second season. 2. Being anchored by roots, plants can withstand the adverse effects of rain and wind. 3. Having been sown in a well-prepared soil, wheat developed well and produced high-quality seed. 4. All farm crops have certain desirable characteristics, the highest yields being obtained from those best adap­ted to the conditions of growing. 5. Soil fertility having been increased, the farmer could obtain a higher yield of potatoes.

V. Найдите в следующих предложениях форму с суффиксом -ing, которой в русском языке соответствует существительное. Переведите Предложения (устно):

1. Conducting water and plant nutrients is the main function of the stem. 2. Conducting water and plant nutrients, the stem performs a very important function for the life of a plant. 3. Improving crop plants was done in the past by selecting superior types. 4. Improving farm crops, plant breeders use three general methods. 5. The yield of potato­es was reduced due to our having planted tubers into too cold soil. 6. Corn requiring much nitrogen, the soil should be well supplied with this element.

VT. В тексте A:

1) найдите причастия и объясните их функции;

2) укажите ing- формы, соответствующие в русском языке су­ществительному;

3) найдите условные предложения, в которых при переводе следует употребить частицу "бы" (4-й и 6-й абзацы).

VII. Переведите текст А (устно). Отработайте чтение текста в лаборатории (лабораторная работа № 1).

Text А

SEEDS AND SEEDING

Good seed is highly essential to successful crop production. Its pu­rity and germinating power should be known before it is planted.

After threshing seeds usually contain foreign materials such as chaff, dirt, weed seeds and seeds of other plants. These can be removed to a large extent¹ but not entirely by cleaning machinery. The presence of weeds in the seed often increases the labour required for the producti-

43

on of the crop, reduces crop yields and contaminates the product avai­lable as well as the seed and soil in future seasons.

Mature seed is preferable to immature seed. Immature seed having a low reserve of food supply because of its small size usually produces poor plants when conditions are adverse at planting time. In addition², immature seeds, high in moisture, are injured by frost.

Most seeds show dormancy, that is, they do not germinate immedi­ately after having become mature even though³ external conditions favour germination. They must pass through a rest or after-ripening period, the duration of the dormancy varying greatly with different spe­cies. One should know the length of the dormancy period of the seed that will be planted. It ranges from a few days to some months or even years. Dormant seeds can survive conditions which would kill them if they were active.

Good stands can be obtained by seeding high-quality seed. Howe­ver, even the best seed will not produce optimum yields, provided other factors are not proper. A moist, firm and warm seedbed that provides favourable environment for germination is of greatest importance in establishing a vigorous and uniform stand. Unless there is enough mois­ture in the soil, poor germination will take place.

Two critical factors must be controlled during seeding: depth and rate. Planting at a proper and uniform depth favours quick and uniform germination. The depth of seeding is influenced by the type of the soil and the size of the seed. If fine seed were placed too deeply it would have some difficulty in reaching the surface of the soil. Coarse seeds should be planted much deeper than fine seeds.

The establishment of high-quality stand is also favoured by a proper seeding rate, both underseeding and overseeding reducing potential yield. The former does not allow full utilization of the available moisture, nut­rients and light while the latter requires more nutrients than are present in the soil and reduces the yield.

Other agronomic recommentations that should be followed in obtaining a good stand are seeding at optimum time, covering seed properly, using proper weed-control techniques, using proper seeding machines and equipment, and applying proper fertilizers.

Пояснения к тексту

1) to ... extent — в ... степени;

2) in addition — кроме того;

3) even though — даже если.

 

 

44

Запомните

if— 1. если, 2. если бы;

unless — если ... не (сказ.);

provided — 1) (причастие П) —обеспеченный;

2) (прош.вр.) — обеспечил (-ли);

3) (союз) — при условии если, в том случае если; should — 1) должен, 2) бы (в условных предложениях); because of (предлог) — из-за; вследствие;

because (союз) — потому что; before — 1) (предлог) — до, перед; 2) (союз) — до того как, перед тем как; after — 1) (предлог) — после; 2) (союз) — после того как.

 

Лексический минимум к тексту А

fine (seed), coarse (seed), mature, immature, stand, uniform, vigo­rous, poor, germinating power, seedbed, firm, moist, warm, moisture, proper, rate, surface, frost, deep, depth, weed, to apply, to reduce, to clean, if, unless, provided, should, because, because of, before, after, germination.

 

АУДИТОРНАЯ РАБОТА

 

VIII. Выборочная проверка упражнений из задания на дом
№ 1.

IX. Расположите слова в алфавитном порядке, учитывая пер-
вые три буквы:

abundant, adaptation, acidity, any, absorption, availability, addition, apply, allow.

X. Определите, к какой части речи относятся следующие слова, и дайте их русские эквиваленты (устно):

1) to produce, a product, production, produced, producing, producer, productive, unproductive;

2) the aim, to aim, aimless, aiming, aimed;

3) water, to water, watering, watered, waterless.

  XI.       Укажите номера предложений, в которых при переводе следует употребить частицу "бы" (устно):

 

 

45

1. If we did not grow legumes, the fertility of the soil would be low. 2. The yield of wheat would be much higher if we applied more fertili­zers. 3. If we were botanists we should know the difference between the roots of cereals and those of legumes. 4. This crop will develop well if planting is done at the due temperature. 5. If the new variety is better than the one replaced, the farmers will grow it widely.' 6. This variety would be grown on our farm, if it were more drought resistant. 7. If the soil contains too much moisture, corn will not do well on it. 8. If the soil had been better, we should have grown corn.

XII.      Определите, в каких предложениях глагол should эквивалентен в русском языке частице "бы" (устно).

1. If you could come to our farm we should show you our experi­mental plots. 2. All cereal crops should be grown on well-prepared soils. 3. We had obtained a good yield, if we should have applied more nitrogen into the soil. 4. Every student should know the difference bet­ween the roots of alfalfa and those of wheat. 5. If this crop were resis­tant to lodging, we should grow it for grain.

XIII. Переведите следующие предложения, обращая внима-
ние на союзы if, unless, provided (устно);

1. Unless there is enough moisture in me soil the seed will not ger­minate. 2. Provided temperature conditions of the late summer are not favourable, grain will not ripen properly. 3. The seed would germinate earlier, if there were more moisture in the soil. 4. If the rate of seeding were too high, the plants would have not enough water and nutrients for their growth. 5. Poor results may be obtained with this crop unless it is sown in a warm and moist soil. 6. Good stands can be obtained, provi­ded high-quality seeds are used. 7. Provided the soil is not moist enough at planting time, irrigation should be applied. 8. If a seed placed under favourable conditions does not germibate, it is in a dormant state.

XIV. Назовите номера предложений, в которых употреблен
независимый! причастный оборот. Переведите (устно):

1.The plants developed well because of their having been planted into warm and moist soil.2. There existing some high-yielding varieties of corn, farmers grow those that are best adapted to their soil and cli­matic conditions. 3. The soil having been supplied with too little nitro­gen, a low yield of corn was obtained. 4. Late planting of this crop is undesirable because the plants may be injured by early frosts in autumn. 5. Obtaining of high-quality stand is influenced by both rate and depth of seeding. 6. Having been sown in a warm and moist soil the seed

 

 

46

began germinating quickly and uniformly. 7. Fertilizers having been ap­plied at the due time, the yield of potatoes increased greatly.

  XV.     Назовите по-английски следующие сочетания слов: основные факторы получения хорошего травостоя; зрелые семена с
хорошей всхожестью, без примесей; влажная, уплотненная, достаточно теплая пашня; быстрые и дружные всходы; соответствующая глубина и норма высева; оптимальные сроки сева, борьба с сорняками, внесение удобрений.

XVI. Контроль чтения и понимания текста А.

Задание на дом № 2

 

XVII. Укажите, в каких предложениях выделенное слово является союзом, а в каких предлогом. Переведите предложения
(устно):

1. The seed does not germinate because of low soil temperature. 2. The seed does not germinate because the soil temperature is too low. 3. The roots of winter crops should develop properly before win­ter. 4. The roots of winter crops should develop properly before winter begins. 5. The seed started to germinate after rain. 6. The seed starts to germinate after the soil has become warm. 7. Many factors are essential for the germination of the seed. 8. The seed will not germinate for a long time, for the soil temperature is too low for it.

XVIII.   Выберите подходящее по смыслу слово (устно):

1. The functions of roots and leaves differ, ... manufacturing, car­bohydrates by the process of photosynthesis (the former, the latter). 2. Soil air contains ... oxygen than the atmospheric air because both plant roots and microorganisms use oxygen for respiration (ore, less). 3. The amount of nitrogen in the soil increased ... the beans had been grown ... two years (before, for, after). 4. The growth of carrots was ... by our having irrigated the crop during the growing season (followed, influen­ced). 5. When high quality seed is not... farmers sow poor seed produ­cing low yields (valuable, available). 6. The quality of the stored seed was reduced ... bad storage conditions (due. to, due). 7. One cannot obtain a high yield... the conditions of growing are favourable (if, un­less). 8. The structure of the soil is affected by ... timo and method of cultivation (proper, properly). 9.... wheat alfalfa has a tap root system (like, unlike).

XIX. Заполните пропуски подходящими по смыслу словами в
соответствующей форме (письменно):

 

 

47

dormancy, to favour, immature, to establish, practice, underseeding, proper, germinating power, overseeding, favourable.

1. Quick and uniform germination can be provided by planting seed
at a ... depth. 2. Both ... and ... reduce potential yield. 3. Applying

proper fertilizers ... seed germination. 4. It is necessary to test..

before the seed is planted. 5. Dormant seed does not germinate even under... conditions. 6. Each species has its... period. 7. A vigorous and

uniform stand can... by proper rate and depth of seeding. 8. Using

proper seeding machines is one of the agronomic ... recommnded for obtaining good stand. 9. Poor plants may be produced by using... seed.

XX. Определите, какие слова из правой колонки могут соче-
таться со словом из левой колонки (устно):

seed — mature, high-quality, dormant, fibrous, hollow, moist, active, useful, immature, weed, successful;

stand — desirable, improved, proper, avai lable, poor, frost-free, cool, careful, scientific, vigorous, uniform;

to produce — yield, seed, stand, dormancy, threshing, seeding machinery, environment, proper, conditions.

XXI.     Переведите следующие предложения на английский язык

(письменно):

а) 1. Чистота и всхожесть — основные качества хороших се-
мян.

2. Незрелые семена не должны использоваться для посева.

3. Семена обычно не прорастают сразу после созревания.

4. Почва для высева семян должна быть достаточно влажной
и теплой. 5. Крупные семена заделываются (высеваются) глуб-
же, чем мелкие. 6. Глубина и норма посева очень важны для полу-
чения высококачественного травостоя.

б) 1. Успешное выращивание культур в большой степени зави-
сит от чистоты и всхожести семян. 2. Семена можно очистить от
примесей, используя специальные машины. 3. Не следует высе-
вать незрелые семена, так как они не дадут сильных и дружных
всходов. 4. Если почва недостаточно влажная и теплая, семена не
прорастут быстро и дружно. 5. Высев семян сверх нормы неже-
лателен, так как растения не будут иметь достаточного количес-
тва питательных веществ и воды для хорошего роста. 6. Высевая
высококачественные семена при благоприятных условиях, можно
получить высокие урожаи сельскохозяйственных культур.

 

48

АУДИТОРНАЯ РАБОТА

XXIII.Проверка домашнего задания.

XXIV.Ответьте на следующие вопросы к тексту А (устно):

 

1. What kind of seed is essential to successful crop production?

2. How can weed seed be removed?

3. Why is immature seed undesirable for planting?

4. What is dormancy?

5. Why shouldn't fine seed be planted too deeply?

6. What agronomic practices should be followed for obtaining high-
quality stand?

XXV. Прочтите текст В, не пользуясь словарем, и укажите
номер абзаца, где говорится о том, какой должна быть почва для
хорошего прорастания семян.

Text В

GERMINATION

1. When environmental conditions are favourable a young dormant plant begins to grow. This change from a dormant condition (состоя­ние) to that of activity is known as germination.

2. Seeds of various kinds of plants require specific conditions for germination. These conditions include adequate moisture, due tempera­ture and proper amount of air. Seeds of a very few plants require light as well. Unless all these conditions are provided, the seeds will not germinate properly.

3. The most favourable temperature for germination varies with the crop. Some seeds require high temperature for good germination, others will germinate best at lower temperature. Oats, for example, germinate at a much lower temperature than corn.

4. When the seed is sown in a firm, moist seedbed, quick and uni­form germination is obtained, provided other conditions are favourable. A firm seedbed is desired because under such conditions the seed and soil come into closer (тесный) contact and moisture becomes available to the seed. Too much moisture is undesirable because it may reduce germination due to deficiency of air.

5. Air is needed for germination, for oxygen is necessary for certain chemical reactions that take place in the plant food stored in the seed.

 

 

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