b'Syngenta cucumber team. Source: SyngentaVARIATION AMONG CUCUMBER TYPES The set of harmful pathogens in the world is now well Bal shares that there is indeed resistance variation per type, butdescribed and traced, says Aust. And thanks to modern methods also for the region or season or the way of growing.of rapid detection using PCR and Real Time PCR, they are much Let me give you an example: for long cucumber heated highmore precise and operational. However, we observe more varia-wire cultivation, powdery mildew and CGMMV resistance are ability in harmfulness of existing pathogens. For example, ZYMV must-have. For long cucumber heated traditional, only powderyhas several dozen strains, and high resistance tested against a mildew resistance. For long cucumber protected, CVYV, CYSDVreference sample may not indicate 100 per cent resistance in and powdery mildew are nowadays the basis for release of newreal conditions with high infectious pressure. This is one of the varieties. reasons why field tests in real environment are still important for Each cucumber type is grown in different markets and eachbreeding in addition to modern laboratory procedures, he adds.market has its own requests for resistances, says Kraan. As aBesides ToLCNDV we should also look at CABYV, says Bal. consequence, there are differences in resistances. Whether aUntil recently it was only found in Russia, but recently this virus resistance is brought in, does not so much depend on the type,became more active in Europe. He adds that CCYV is spreading but mainly on the region where the types are grown. rapidly from Asia via the Mid-East countries.Also, for Aust, it is clear that the resistance of a different type of cucumber can vary significantly. This difference inTOLERANCE TO ABIOTIC STRESSresistance to fluctuations in temperature between smooth andWe are breeding in areas where cucumbers are grown, says coarse hybrids is striking. Similarly, in parthenocarpic gherkinsKraan. With increased drought/heat stress, our new varieties are cultivated in shelters together with greenhouse cucumbers, weselected to perform well in the markets where that plays a role.notice higher resistance of powdery mildew and viruses. Abad also works on tolerance. Although probably it is not in the European materials where we have the most significant NEW DISEASES challenges, but more in the Long Chinese for cold tolerance and Gonzlez-Cabezuelo says about three years ago, the appearancein the Indian Bicolour for heat tolerance. We are learning also of a new viral disease related to ToLCNDV was reported in Spain,from those types to increase levels in European materials. very aggressive with certain cucurbits such as melon, cucumberAbiotic influences are an increasingly important factor and especially zucchini, which caused great concern in the field.affecting all crops today, and cucumbers are among the most Until now, the control of the disease has been carried out bysensitive crops to the environment. means of the control of its vector the white fly species BemisiaTherefore, we must take into account the ability to pro-tabaci. However, the development of varieties with genetic resist- duce in difficult conditions. Here again, we cannot do without ance to the disease is a medium-term objective for our company. testing in various conditions. Today we can mention that we Suelmann shares that where ToLCNDV first was thoughthave a positive reaction from farmers to one of our cucumber to be of minor importance as the symptoms were rather mild,varieties, which in competition against foreign varieties with-nowadays it is a more serious problem like in Spain. stood the high summer temperatures several years ago in Spain. EUROPEAN-SEED.COMIEUROPEAN SEED I 19'